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VG Scienta EpiSoft - IGC3 Communications Handbook

IGC3

CommunicationsHandbook

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User HandbookEpiSoft - IGC3 Communications Handbook

Document Number UI7210Change Control

Issue Date (mm/yy) ECN#A 12/06 Original Issue

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1 Introduction 41.1 About this handbook 4

2. Communication Hardware 52.1 Introduction to the Communications Hardware 52.2 Setting up for RS232 or RS485 communications 52.3 Configuration of the IGC3 Serial Connectors 62.4 9- and 25-pin PC RS232 to IGC3 Interface wiring 72.5 IGC3 Daisy-chaining 7

3 The MODBUS Interface 83.1 Why MODBUS? 83.2 Parameters and Parameter Addresses 83.3 MODBUS Implementation and Floating Point Data Transfer 83.4 Digital Parameters Integers, Flags and the VALID flag 93.5 The Invalid Data Value - FFFFFFFFh 93.6 MODBUS Message Structure 93.7 Frame Start 9

3.8 Device Address First Byte 103.9 Function Code 17h Second Byte 103.10 The Data Package sent from host to the IGC3 103.11 Data Package response from the IGC3 113.12 Cyclic Redundancy Check: CRC 113.13 Transmission Termination 133.14 Error Response 133.15 Transmission Rates 13

4 MODBUS Parameter Address Structure 14

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1 Introduction

1.1 About this handbook

This handbook describes serial communications with the IGC3 gauge controllerusing the MODBUS protocol (also conforms with JBUS protocol). Choice of MODBUS as thestandard comms package for the IGC3 was dictated by its wide usage, efficiency of datatransfer coupled with low processing overheads and the inherent integrity of data transfer.

The key features of the IGC3 communications are:

RS232 and RS485 (3 wire) interfaces are provided as standard. [RS422 (5 wire) was alsoincluded in controllers using software version 1.xx.]

RS232 interface is multi-drop, i.e. up to 8 devices can be connected to a standardcomputer RS232 port (though this may vary depending on computer chip set used).

Up to 16 devices connected to an RS485 port. 2 RJ45/8 connectors are provided making for simple daisy chaining using industry

standard moulded cables. The protocol is a fully compliant MODBUS implementation but incorporating floating

point transfer of data. Implementation uses function code 17h, which allows data to be written to and read

from the IGC3 within a single message, thus doubling data throughput. Parameters are organised in functional groups to allow optimised transfer of data.

Section 2 describes the interface hardware and wiring to the IGC3.

Section 3 provides an overview of MODBUS

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2. Communication Hardware

2.1 Introduction to the Communications Hardware

The rear of the IGC3 has 2x screened RJ45/8/8 connectors. These are internallyconnected in parallel to allow simple daisy chaining of multiple IGC3s.

Each RJ45 has 8 pins. These provide everything required to implement RS232or RS485 interfaces both are provided within the IGC3 as standard. Note:

IGC3 implements a multi-drop RS232 interface; that is a number of IGC3s can beconnected to a standard RS232 port, such as that provided on a PC.

Both interface types (RS232 and RS485) are active at all times; that is, thereceive lines for both types are listened to continually, similarly, data istransmitted from both types. For this reason, it is important that only 1interface type be connected at the host controller/PC.

The following table summarises the main characteristics of the three buses:

RS232 RS485

Transmission Signal Single ended Differential

Connection Scheme 3 wire:Ground, Transmit, Receive1

3 wireGround,

twisted pair shared forTransmit and Receive

Master/Slave configuration 1 master, up to 8 slaves 1 master, 16 slaves2

Max cable length 12metres 1000metres

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1. Base address(es). Each device on a bus has a unique address in the range 1 to 99.Addresses can be assigned to units on a bus in any order of daisy-chaining.

2. Bus type.All devices must be wired for the same bus type, RS232 or RS485.

Both interfaces are active at all times; selection is implemented by the connections madeto the controlling device (e.g. PC).

3. Baud rate.All devices MUST have the same Baud Rate. Scroll through the Setupmenu to select. Recommended value: 19200.

4. Parity.All devices MUST ave the same Parity. Scroll through the Setup menu toselect. Since the MODBUS protocol provides a high degree of message integrity, noparity is recommended.

Note that the IGC3 uses: 1 start bit, 8 data bits, and 1 stop bits (plus parity bit if used).

2.3 Configuration of the IGC3 Serial Connectors

IGC3 provides RS232 and RS485 communications as standard via two parallelwired shielded RJ45 8pin connectors. The connectors are standard telephone types knownas shielded RJ45 8/8. These have 8 pins and a shield contact that couples with screen ofthe cable:

Plug and play solution to wiring using industry-standard connectors for data

networking/communications Inexpensive, ready-made moulded cable assemblies are readily available from

electrical/telecommunications suppliers

Cable assemblies are available as UTP (unscreened) and FTP (screened). Westrongly recommend use of the screened FPT variety, since they providesignificant benefits in terms of noise exclusion. They are generally referred to as

SHIELDED, Cat5e COMPLIANT, RJ45 PATCH LEADS.

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Pin assignments are as follows:

Pin Colour** Function1 White/orange RS232 0V (Earth)

2 Orange RS232 receive

3 White/Green RS232 transmit

4 Blue RS485 0V return

5 White/blue RS485 0V return

6 Green RS485 0V return

7 White/brown RS485 transmit A

8 Brown RS485 transmit BShield Earth

** May vary between cable manufacturers

When daisy-chaining IGC3s, use standard SHIELDED, Cat5e COMPLIANT,RJ45 PATCH LEADS. Selection of which communications bus type (RS232 or RS485) isused depends on which wires are connected to the host PC/PLC. For example, if you are todrive several IGC3s from a standard PC port, only wires corresponding to pins 1, 2 and 3 will

need to be connected at the PC see subsequent sections for more detail.Note that the RS485 0V return signal at pins 4, 5 and 6 are internally connectedto earth via a 100 resistor to reduce the likelihood of earth loops when using the RS485interface.

2.4 9- and 25-pin PC RS232 to IGC3 Interface wiring

PC 25 pinFemale DB25

PC 9 pinFemale DB9

pin

Function Cable Function IGC3

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3 The MODBUS Interface

All aspects of IGC3 operation can be controlled from a host computer/PLC. Thedefault communications protocol employed is MODBUS, conforming to class 0 of the OpenMODBUS/TCP Specification (available fromhttp://www.modicon.com/openmbus/standards/openmbus.htm). IGC3 uses function code17h for enhanced data throughput and floating point transfer for data.

3.1 Why MODBUS?

Industry standard and well documented Robust, reliable and compact. High reliability using CRC error detection Low computing/processing overheads Up to 16 parameters can be read and/or written within each message Implementation allows floating point data transfer for full resolution using simple

casting, dramatically reduces programming overheads Enhancements for double speed throughput of data Implied length philosophy allows host and slave to verify message completion

3.2 Parameters and Parameter Addresses

Data is held in a series of registers which have addresses starting at 0. Theseare referenced in hexadecimal notation with suffix h e.g. 000Ah (for address 10). Eachregister is a 16 bit quantity (a WORD comprising of two 8 bit BYTES). A WORD can thereforehave a value between 0 and 216 (this corresponds to unipolar 0 65536, or bipolar 32767).

Data values within the IGC3 (known as Parameters) are 32 bit in size, thus 2

egiste s a e eq i ed to hold each Pa amete al e (compl ing ith Appendi B 2 of the
http://www.modicon./http://www.modicon./

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The floating point data format used is the standard 32 bit floating point IEEEformat, as employed in most high level languages such as C, BASIC, Pascal, SCADA etc.with the following bit allocations:

SIGN EXPONENT FRACTION

Bit31

Bit 30 to Bit 23 Bit 22 to Bit 0

27 to 20 2-1 to 2-23

Conversion from the byte string to the floating point value is implemented by placing thestring in memory and casting to the 32-bit float type. Note, some compilers may need the

bytes to be swapped from low to high.

3.4 Digital Parameters Integers, Flags and the VALID flag

Digital parameters fall into 2 types. The first type store integer numerical dataas a 32 bit number, for example, the degas time in minutes.

The second type store status information, where groups of bits indicate thecondition of a device (e.g. the ion gauge status parameter). To allow maximum rate of datatransfer, some parameters hold several related pieces of information.

To avoid problems where only one piece of information needs to be written tochange it without the need to have read all information, for each group of bits associatedwith a status condition, the uppermost bit is used as a validation bit i.e. it is always setduring a read operation to indicate that it is valid, and must be set if the specific set offlags are to be changed during a write operation. This approach means that only thesetting required for the particular piece of information needs be transmitted (with itsvalidation bit set). For example, to change the emission for the ion gauge to 1mA withoutaffecting any of the other status information for the ion gauge setting parameter, set the

IGS EM VALID bit (00000080h) d th IGS EM 1 A bit (00000004h) th th l t

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Frame Startis a period of bus inactivity of at least 3.5 times the time neededto transmit a single character. For example, at 9600 baud, and character transfer comprising1 start bit, 8 data bits, 2 stop bits, the Frame Start period would be >=3.5ms.

3.8 Device Address First Byte

Since several devices share the bus, each device MUST have a unique identifyingaddress. The Device Addressis a one BYTE value and has a range between 1 and 99.

The IGC3 does NOT implement or use the broadcast address (0)when all units must perform a given action.

3.9 Function Code 17h Second Byte

IGC3 only uses function code 17h which allows the host to write AND read up to16 parameters within a single communication exchange. Data does not have to betransferred at every communications exchange. All other function codes are ignored by IGC3.

3.10 The Data Package sent from host to the IGC3

The first 4 BYTES of the data package related to function code 17h indicates the

address of the first parameter to be read (2 BYTES where the first BYTE is always 00h)followed by the number of WORDS to read. Since up to 16 parameters can be read at a time,and each parameter is 32 bits (2 WORDS), the 3rd BYTE is always 00h and the 4th BYTE isalways even and has a value between 0 and 32. To summarise:

Parameter Address of firstWORD

Number of WORDs to read

MSB LSB MSB LSB

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The data package comprises the following sequence:00h 00h 00h 00h 4 BYTES indicating that no WORDS to read00h 01h 2 BYTES indicating the address of the first parameter that will be written to

00h 02h 2 BYTES indicating the number of WORDS to write (1 parameter, therefore 2WORDS)04h 1 BYTE indicating that 4 bytes (i.e. 1 parameter == 2 WORDS == 4 BYTES)02h 82h 84h 42h 4 BYTES of data

The data package comprises 9+(4x1)=13 BYTES and the message is 17 BYTES.

Example 3: Read 3 parameters starting at parameter 003Eh from the IGC3 ANDWrite 1 parameter starting at parameter 0004h to the IGC3:

The data package would comprise the following sequence:00h 3Eh 2 bytes indicating the address of the first parameter to be read00h 06h 2 bytes indicating the number of WORDS to read (2 WORDS per parametertherefore 6 WORDS)00h 01h 2 BYTES indicating the address of the first parameter that will be written to00h 02h 2 BYTES indicating the number of WORDS to write (1 parameter, therefore 2WORDS)04h 1 BYTE indicating that 4 bytes (i.e. 1 parameter == 2 WORDS == 4 BYTES)

02h 82h 84h 42h 4 BYTES of dataThe data package length is 9+(4x1)=13 BYTES and the message is 17 BYTES.

3.11 Data Package response from the IGC3

On receipt of a valid message requesting data, the IGC3 responds with a framecontaining a data package comprising of:

N b f D t

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// The initial message is pointed to by lpMess and the total message// length (including address and function code bytes) are indicated// in nMessLen

int zet_calc_modbuscrc(unsigned char* lpMess, int nMessLen, unsigned char* lpCRC){int j;unsigned int wCarry, wNext, wCRC;

// Initialise the CRC registerwCRC = 0xFFFF;while (nMessLen--){

// Cast the byte to a 16 bit valuewNext = (unsigned short)lpMess;// Exclusive OR it with the CRC registerwCRC ^= wNext;// Shift loop 8 timesfor (j=0; j>= 1;// If the saved bottom bit was set, EXOR with A001hif (wCarry)wCRC ^= 0xA001;

}// Next bytelpMess++;}// Set upper byte of CRC register to second CRC byte

l CRC[1] ( i d h )( CRC >> 8)

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zet_calc_modbuscrc(sMess, nMessLen-2, sCRC);// Note use of nMessLen-2 since we do not want to include// received back CRC in the CRC generation process

if ((sMess[nMessLen-2] == sCRC[0]) && (sMess[nMessLen-1] ==sCRC[1])){// SUCCESS!!!!}else{// ERROR PROCESSING!!!!}

3.13 Transmission Termination

A message is terminated by inactivity on the bus for a period >3.5 times thetime taken to transmit 1 character (i.e. the frame start delay) after which the slave interpretsthe message. The structure of the MODBUS protocol allows the number of BYTES in aresponse to be predicted; this serves to receipt of a correct or error response.

The frame start/end delay also tells the slave that the next BYTE to arrive will bean address commencing the next frame.

3.14 Error Response

A device will only respond if its address and a valid function code are receivedafter the frame start period, and the CRC value is verified, otherwise no response is given.

If an error is detected in the data section, it will respond with an error code:

Device Address Function Code +80h

Error Code CRC

1 BYTE 97h 01h 02h MSB LSB

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4. MODBUS Parameter Address Structure

4.1 IGC3 Parameter Address Structure

ALL IGC3 PARAMETERS, BOTH FLOATING POINT AND INTEGER, ARE 32 BIT; 2WORDS (4 BYTES) ARE REQUIRED FOR TRANSMISSION OF EACH PARAMETER

ALL PARAMETER ADDRESSES ARE EVEN FLOATING POINT PARAMETERS START AT ADDRESS 0090h

INTEGER PARAMETERS ARE LOCATED BELOW ADDRESS 0090h

4.2 Parameter Grouping

IGC3 stores related parameters at adjacent addresses so that data relating to afunctional group can be accessed within a single message.

When writing parameter values to the IGC3, if one or more of the values is notto be changed, then the parameter values that are not to be changed can be set to theInvalid Data Value FFFFFFFFh. For example, to change only the bake-out temperatures at

steps 1 and 4 whilst sending a parameter sequence covering temperatures 1 to 4, theparameter values for steps 2 and 3 should be set to FFFFFFFFh.

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5. IGC3 Parameter Addresses

5.1 Introduction

This section lists the complete parameter address list for the IGC3.

Note: There are 120 parameters with address of 00h, 02h, 04h EEh. Note that not all

parameters are used.

The parameters are treated as 15 groups of 8 parameters. Each group representseither related parameters, or a functional group. Parameters 00h to 8Eh inclusive are 32 bit (4 BYTE) integer parameters. Parameters 90h to EEh inclusive are 32 bit floating point parameters. The most frequently required parameters have intentionally been grouped

together (starting at 0x80 and finishing at 9Eh) so that they can be readwithin a single message.

5.2 Parameter List

The following table lists and describes the parameters in detail:

Parameter Address gives the decimal and hexadecimal value of the parameter address;e.g. 42 2Ah means that the parameter at address 42 (2Ah) is the measured value.Parameter Name relates the parameter to the internal function see IGC3 Handbook fordetails.Type indicates whether the parameter is a 32 bit integer or a 32 bit floating point value.

R/W i di t th R d d W it t t P t k d R b d l

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Page 16 of 26

ParameterAddress

ParameterName

Type R/W Description

GROUP 1

0 00h Unit ID 32 bit integerR Returns a value of 69435650h. [ASCII representation of IGC3].

2 02h SoftwareVersion

32 bit integer R Returns a value of 0x4544xxyyh, where xxis major version, and yyis sub-version; e.g. 45440206h indicates version 2.06

4 04h [Unassigned] 32 bit integer R

6 06h [Unassigned] 32 bit integer R

8 08h Communications 32 bit integer R For internal use only. Holds information about comms address, settings, protocol etc.

10 0Ah [Internal] 32 bit integer R

12 0Ch [Unassigned] 32 bit integer R

14 0Eh [Unassigned] 32 bit integer R

GROUP 2

16 10h Unit Name 32 bit integerrepresenting 4

ASCII characters

R/W A name of up to 4 characters can be assigned to each channel. The order of the characters is DDCCBBAAh where AA is thefirst character in the name, BB the next etc. Valid characters are in the range 20h (space) to 7Ah (z) inclusive. Anycharacters outside this range will be changed to 20h (space). Any spaces at the start of the name are removed so that the

name starts with a character in the range 21h to 7Ah. Example: the name Si would be 20206953h.

18 12h User ID 32 bit integer R/W User defined identifier. Can be used, for example, to automatically configure or identify specific units with a software object.

20 14h [Unassigned] 32 bit integer R/W


24 18h Degas RampTime

32 bit integer R/W 0 to 999 minutes. Duration of Degas power rise

26 1Ah Degas Time 32 bit integer R/W 0 to 999 minutes. Duration of Degas.

28 1Ch Degas Power 32 bit integer R/W Ultimate degas power reached at end of degas ramp time; power applied during the degas time or if Quick degas isinitialised.Values are: IGS_EM_1W (08h), IGS_EM_2W (09h), IGS_EM_3W (0Ah), IGS_EM_6W (0Bh), IGS_EM_12W (0Ch),IGS_EM_20W (0Dh), IGS_EM_30W (0Eh).

30 1E [Unassigned] 32 bit integer R/W

GROUP 3





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ParameterAddress

ParameterName



42 2Ah [Unassigned] 32 bit integer R/W

44 2Ch [Unassigned] 32 bit integerR/W

46 2Eh [Unassigned] 32 bit integer R/W

GROUP 4







60 3Ch [Unassigned] 32 bit integer R/W


GROUP 5

64 40h Global Settings 32 bit integerR/W

R/W

R/W

R/W

R/W

GLOBAL FLAGSBits F0000000h Display setting. Selects what IGC3 display shows on front panel.GS_DISPLAY_VALID (80000000h). Must be set to write value.Bits 30000000h indicate the display type: GS_DISPLAY_SUMMARY (00000000h) default ion gauge display, GS_DISPLAY_SLOTS (10000000h) summary value for the 2 slots, GS_DISPLAY _BAKEOUT (20000000h) bake-out status, GS_DISPLAY_TIMER (30000000h) timer statusBits 00F00000h Display BrightnessGS_BRIGHTNESS_VALID (00800000h) Must be set to write value.Bits 00300000h indicate the brightness level: GS_BRIGHTNESS _25 (00000000h) default 25%, GS_BRIGHTNESS _50(00100000h) 50%, GS_BRIGHTNESS _75 (00200000h) 75%, GS_BRIGHTNESS _100 (00300000h) 100%Bits 00000F00h Ion gauge degas start-up protectionGS_IGDEGAS_VALID (00000800h) Must be set to write value.Bit 00000100h indicates whether protection is on or off: GS_IGDEGAS _ON (00000100h) protect is onBits 000000F0h Pressure UnitsGS_UNITS_VALID (00000080h) Must be set to write value.

Bits 00000030h select units: GS_UNITS _MBAR (00000000h) default mBar, GS_UNITS _TORR (00000010h) Torr, GS_UNITS_PASCAL (00000020h) PascalBits 0000000Fh Ion gauge pressure display resolutionGS_IGDPS_VALID (00000008h) Must be set to write valueBit 00000001h selects number of decimal places: _1 (00000000h) default 1 decimal place, _2 (00000001h) 2 decimal places

66 42h Slot A 32 bit integerR

TYPE OF MODULE IN SLOT ABits 000000FFh Module type

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ParameterAddress

ParameterName


TYPE_VALID (00000080h)TYPE _EMPTY (00000000h) default no module fitted, TYPE _PIRANI (00000001h) VG Pirani gauge head, TYPE _TC(00000002h) thermocouple module

68 44h Slot B 32 bit integer R TYPE OF MODULE IN SLOT BSee Slot A70 46h PDFlags 32 bit integer

R/W

R/W

R

R

PUMP-DOWN SETTINGSBits 00F00000h Start/Stop Pump DownPDF_SS_VALID (00800000h) Must be set to write value.PDF_SS_START (00100000h) start pump downPDF_SS_STOP (00200000h) stops pump downBits 0000F000h Digital Inputs assignmentPDF_DI_VALID (00008000h) Must be set to write value.Bits 00003000h set which digital inputs interlock Pump-down: PDF_DI_1 (00001000h) digital input 1 interlocks pump down,PDF_DI_2 (00002000h) digital input 2 interlocks pump down (Note: both can be set)Bits 00000FF0h Internally used for status indicationPDF_VALID (00000800h) always setRemaining bits are set in combination as pump-down progresses:PDF_PUMPDOWN (00000010h) pump down started, PDF_INITED (00000020) initialisation flag, PDF_INDELAY (00000040h)in delay time, PDF_IGSTART (00000080h) attempting to start the ion gauge, PDF_DIINHIBITED (00000100h) pump downinhibited by one or both digital inputsBits 0000000Fh Attempt countThe number of attempts made to start the ion gauge (value between 0 and 9)[see also PD IG Start Pressure, PD IG Delay, PD IG Attempts]

72 48h BO Flags 32 bit integerR/W

R/W

R/W

R/W

BAKE-OUT FLAGSBits 0F000000h Auto-degas at end of bake-outBOF_DG_VALID (08000000h) Must be set to write valueBOF_DG_ON (01000000h) auto-degas on at end of bake-outBits 00F00000h Action of assigned digital inputs on Bake-outBOF_DIS_VALID (00800000h) Must be set to write valueBits 00300000h select action: BOF_DIS_NORMAL (00000000h) default: output is off if assigned digital inputs fail,BOF_DIS_SUSPEND (00100000h) as normal but bake-out timer also stops, BOF_DIS_TERMINATE (00200000h) bake-outterminates if assigned digital inputs fail.Bits 000F0000h Action of ion gauge pressure on Bake-outBOF_IGS_VALID (00080000h) Must be set to write value

Bits 00030000h select action: BOF_IGS_NORMAL (00000000h) default: output is off if ion gauge pressures rises abovePressure Limit parameter value, BOF_IGS_SUSPEND (00010000h) as normal but bake-out timer also stops,BOF_IGS_TERMINATE (00020000h) bake-out terminates if pressure rises above Pressure Limit parameter value.Bits 0000F000h Digital Input assignmentBOF_DI_VALID (00008000h) Must be set to write valueBOF_DI_1 (00001000h) assigns digital input 1, BOF_DI_2 (00002000h) assigns digital input 2. [Both can be assigned].

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ParameterAddress

ParameterName


R/W

R

Bits 00000F00 Start/Stop Bake-OutBOF_SS_VALID (00000800h) Must be set to write valueBOF_SS_START (00000100h) starts bake-out, BOF_SS_STOP (00000200h) stops bake-out

Bits 000000FFh Status InformationBOF_VALID (00000080h) Always setRemaining bits are set in combinations to reflect status:BOF_BAKE_OUT (00000001h) bake-out started, BOF_DIINHIBITED (00000002h) bake-out is inhibited by assigned digitalinputs, BOF_IGINHIBITED (00000004h) bake-out is inhibited by ion gauge pressure, BOF_SUSPENDED (00000008h) bake-out is suspended, BOF_ON (00000010h) bake-out output is on.[See also BO Step temperatures 1-6, BO Step times 1-6, BO IG Pressure Limit, BO Hysteresis]

74 4Ah Timer Flags 32 bit integerR/W

R/W

R

TIMER FLAGSBits F0000000h Restart Start/Stop PeriodsTMR_START_VALID (80000000h) Must be set to write valueTMR_START_OFF (10000000h) Restart timer at beginning of OFF period, TMR_START_ON (20000000h) Restart timer atbeginning of ON periodBits 0000F000h Digital Input assignmentTMR_DI_VALID (00008000h) Must be set to write value.Bits 00003000h set which digital inputs interlock timer operation: TMR_DI_1 (00001000h) digital input 1 interlocks timer,TMR_DI_2 (00002000h) digital input 2 interlocks timer (Note: both can be set)Bits 0000000Fh Timer StatusTMR_VALID (00000008h) always setRemaining bits are set in combinations to reflect status:TMR_ON (00000001h) timer is in ON period, TMR_DIINHIBITED (00000002h) timer is inhibited by assigned digital inputs,TMR_IGINHIBITED (00000004h) timer is inhibited by ion gauge pressure[See also Timer OFF Duration, Timer ON Duration, Timer IG Pressure Limit]

76 4Ch Digital Input 1Flags

32 bit integerR/W

DIGITAL INPUT 1 FLAGSBits 0000000FhDI_STATUS_VALID (00000008h) Must be set to write valueDI_STATUS_ON (00000001h) Digital input 1 is on (read only bit), DI_STATUS_INHIBIT (00000002h) Inhibit digital input 1,DI_STATUS_OVERRIDE (00000004h) Override Digital input 1[See also Digital Input 1-2 Status Summary]

78 4Eh Digital Input 2Flags

32 bit integerR/W

DIGITAL INPUT 2 FLAGSSee Digital Input 1 flags for bit assignments

GROUP 680 50h Trip1 Flags 32 bit integer

R/WTRIP 1 FLAGSBits 000F0000h Operation of Trip 1 during Degas (version 2.0 and above only)DO_DEGAS_VALID (00080000h) Must be set to write valueDO_DEGAS_TRIP (00010000h) Trip 1 operates during degas in same way as for normal emission operation. If this flag isset, trip 0 fails when degas is started

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ParameterAddress

ParameterName


R/W

R/W

R/W

Bits 0000F000h Trip 1 assignmentDO_ASSIGN_VALID (00008000h) Must be set to write valueThe remaining 3 bits indicate what trip 1 is assigned to:

DO_ASSIGN_NONE (00000000h) no assignment, DO_ASSIGN_IG (00001000h) ion gauge, DO_ASSIGN_SLOT A (00002000h)Slot A value, DO_ASSIGN_SLOTB (00003000h) Slot B value, DO_ASSIGN_PUMPDOWN (00004000h) trip 1 is set whilst pumpdown is operating, DO_ASSIGN_BAKE_OUT (00005000h) trip 1 operates with the on/off state of the bake-out,DO_ASSIGN_TIMER (00006000h) trip 1 state is determined by the on/off status of the timer, DO_ASSIGN_DEGAS(00007000h) trip 1 is set to on during degas.Bits 00000F00h Trip 1 directionDO_ACTION_VALID (00000800h) Must be set to write value.DO_ACTION_GREATERTHAN (00000100h) Trip 1 is on when the controlling value exceeds the Trip 1 Level parameter value.If this bit is not set, Trip 1 is on when the controlling value is less than the Trip 1 Level parameter value.Bits 0000000Fh Trip 1 stateDO_STATUS_VALID (00000008h) Must be set to write valueDO_STATUS_ON (00000001h) Trip 1 is on (read only bit), DO_STATUS_INHIBIT (00000002h) Inhibit trip 1,DO_STATUS_OVERRIDE (00000004h) Override Trip 1[See also Global Settings (for ion gauge degas protect), Trip 1 Level, Trip Hysteresis, Trip 1-7 StatusSummary]

82 52h Trip 2 Flags 32 bit integerR/W TRIP 2 FLAGS

See Trip 1 Flags for all bit assignments

84 54h Trip 3 Flags 32 bit integer R/W TRIP 3 FLAGSSee Trip 1 Flags for all bit assignments



90 5A Trip 6 Flags 32 bit integer R/W TRIP 6 FLAGSSee Trip 1 Flags for all bit assignments

92 5C Trip 7 Flags 32 bit integer R/W TRIP 7 FLAGSSee Trip 1 Flags for all bit assignments

94 5E D/A Flags 32 bit integer R/W DIGITAL/ANALOGUE CONVERTER SETTINGSBits 00000F00h Linear/logarithmic responseDA_FUNC_VALID (00000800h) Must be set to writeDA_FUNC_LIN (00000100h) sets output to linear relationship. Default is logarithmic (as generally used with pressureassignment)Bits 0000000Fh D/A AssignmentDA_SET_VALID (00000008h) Must be set to writeRemaining 3 bits select one of the following assignments: DA_SET_MIN (00000000h) output is permanently at D/A Min valueparameter, DA_SET_IG (00000001h) assigned to ion gauge, DA_SET_SLOTA (00000002h) assigned to slot A,AD_SET_SLOTB (00000003h) assigned to slot B, AD_SET_IGSLOTA (00000004h) assignment moves from ion gauge when

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Page 21 of 26

ParameterAddress

ParameterName


ion gauge is on to module in Slot A (usually Pirani) when ion gauge is off thus potentially providing coverage fromatmosphere to UHV, DA_SET_EXTERNAL (00000005) output corresponds to value set over comms to parameter D/A output,DA_SET_HZ (00000006) output toggles between D/A min and D/A max value at frequency of ~2Hz, DA_SET_MAX

(00000007) output fixed at D/A max valueGROUP 7

96 60h Minimum IGEmission

32 bit integer R/W MINIMUM ION GAUGE EMISSIONBits 000000FFhIGS_EM_VALID (00000080h) Must be set to writePossible values are: IGS_EM_100uA (00000001h), IGS_EM_200uA (00000002h), IGS_EM_500uA (00000003h),IGS_EM_1mA (00000004h), IGS_EM_2mA (00000005h), IGS_EM_5mA (00000006h), IGS_EM_10mA (00000007h).Range is IGS_EM_100uA to the Maximum IG emission

98 62h Maximum IGEmission

32 bit integer R/W MAXIMUM ION GAUGE EMISSIONBits 000000FFhIGS_EM_VALID (00000080h) Must be set to writePossible values are: IGS_EM_100uA (00000001h), IGS_EM_200uA (00000002h), IGS_EM_500uA (00000003h),IGS_EM_1mA (00000004h), IGS_EM_2mA (00000005h), IGS_EM_5mA (00000006h), IGS_EM_10mA (00000007h).Range is Minimum IG emission to IGS_EM_10mA







GROUP 8






122 7Ah [Unassigned] 32 bit integerR/W



GROUP 9

128 80h Trip 1-7 Status 32 bit integer R SUMMARY OF STATUS OF ALL 7 TRIPS

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ParameterAddress

ParameterName


Summary Each group of 4 bits summarises the status of one of the trips. 0000000Fh for trip 1, 000000F0h for trip 2etcIn each case: DOx_VALID (8h) always set, DOx_ON (1h) set when the trip is on, DOx_INHIBIT (2h) set in inhibit,

DOx_OVERRIDE (4h) set in override. (Note: DOx_ON always set if DOx_OVERRIDE is set.)[See also Global Settings (for ion gauge degas protect), Trip 1 Level, Trip Hysteresis, Trip 1 Flags Trip 7Flags]

130 82h Digital Input 1-2Status Summary

32 bit integer R SUMMARY OF STATUS OF BOTH DIGITAL INPUTSBottom 2 groups of 4 bits indicate the status of the digital inputs. 0000000Fh for DI 1 and 000000F0h for DI2In each case: DIx_VALID (8h) always set, DIx_ON (1h) set when input is on, DIx_INHIBIT (2h) set to inhibit, DIx_OVERRIDE(4h) set in override. (Note: DIx_ON always set if DIx_OVERRIDE is set.)[See also Digital Input 1 and Digital Input 2 Flags]

132 84h Slot A Status 32 bit integer R/W Reserved for future implementation

134 86h Slot B Status 32 bit integer R/W Reserved for future implementation

136 88h Ion GaugeStatus

32 bit integer

R

R

R

R

R

R

STATUS OF ION GAUGE This parameter reports status of ion gauge. Note that parameters that can bechanged are written to through the Ion Gauge Settings parameter (8Eh).Bits FF000000h Ion Gauge Operating Status/Failure ModeIGS_OP_VALID (80000000h)

Remaining bits indicate the failure mode: IGS_OP_DIFAIL (20000000h) digital input fail, IGS_OP_OVERP (10000000h)overpressure fail, IGS_OP_EMFAIL (08000000h) emission failed, IGS_OP _INTERLOCKTRIP (04000000h) ion gauge leadinterlock not made, IGS_OP _EMTRIP (02000000h) emission tripped, IGS_OP _FILTRIP (01000000h), filament over-currenttripBits 00F00000h Filament TypeIGS_FILTYPE_VALID (00800000h). Must be set to write the value. [Cannot be set if ion gauge is on]. IGS_FILTYPE _W(00100000h) Tungsten. If this bit is not set, IridiumBits 000F0000 Filament NumberIGS_FILNUM_VALID (00080000h). Must be set to write the value. [Cannot be set if ion gauge is on]. IGS_FILNUM _2(00010000h) Filament 2. If this bit is not set, filament 1Bits 0000F000 Measurement errorIGS_IND_VALID (00008000)IGS_IND_MINLIMIT (00004000h) if electrometer input below measurement limit (e.g. collector lead disconnected)Bits 00000F00 Ion gauge pressure trendIGS_TREND_VALID (00000800)

IGS_TREND_UP (00000100) pressure is rising. IGS_TREND_DOWN (00000200) pressure is fallingBits 000000FF Current ion gauge emission/degas settingIGS_EM_VALID (000000FFh). Always setThe emission/degas status of the ion gauge is set via one of the following:IGS_EM_OFF (00000000h), IGS_EM_100uA (00000001h), IGS_EM_200uA (00000002h), IGS_EM_500uA (00000003h),IGS_EM_1mA (00000004h), IGS_EM_2mA (00000005h) , IGS_EM_5mA (00000006h), IGS_EM_10mA (00000007h),

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ParameterAddress

ParameterName


IGS_EM_1W (00000008h), IGS_EM_2W (00000009h), IGS_EM_3W (0000000Ah) , IGS_EM_6W (0000000Bh) , IGS_EM_12W(0000000Ch), IGS_EM_20W (0000000Dh), IGS_EM_30W (0000000Eh).The above values are ORed with: IGS_EM_AUTO (00000040h) if the ion gauge is being run in auto-emission mode where

the value indicates the current emission value, or IGS_EM_QUICKDEGAS (00000010h) during quick degas where the valueindicates the power.[See also Ion Gauge Settings: 8Eh]

138 8Ah Fan Status 32 bit integer R/W FAN STATUSBits 0000000Fh Fan StatusFAN_VALID (00000008h) always setFAN_ERROR (00000001h) Fan error has occuredFAN_ON (00000002h) Fan is running

140 8Ch Ion GaugeSettingsExtended

32 bit integer R/W EXTENDED ION GAUGE SETTINGSBits 0000000Fh Digital Input 1 action on ion gauge operationIGSX_DI1_VALID (00000008h) Must be set to write valueThe remaining 3 bits set the action: IGSX_DI1_NONE (00000000h) no assignment, IGSX_DI1_INTERLOCK (00000001h)gauge trips if DI1 fails, IGSX_DI1_EMON (00000002h) ion gauge is on whilst DI1 is on, IGSX_DI1_EMTOGGLE (00000003h)ion gauge turns on/off in response to a short pulse applied to DI1, IGSX_DI1_DEGASON (00000004h) ion gauge degasoperates whilst the digital input is on, IGSX_DI1_DEGAS (00000005h) degas starts/stops in response to a short pulseapplied to DI1.Bits 000000F0h Digital Input 2 action on ion gauge operationThese bits mirror the above operation but for digital input 2. Flags are IGSX_DI2_xxxxx and bits are shifted up 4

142 8Eh Ion GaugeSettings

32 bit integer

R/W

R/W

R/W

ION GAUGE SETTINGS This parameter sets changes to the ion gauge. To obtain latest status informationabout the ion gauge, use the Ion Gauge Status Parameter (88h)Bits 00F00000h Filament TypeIGS_FILTYPE_VALID (00800000h). Must be set to write the value. [Cannot be set if ion gauge is on]. IGS_FILTYPE _W(00100000h) Tungsten. If this bit is not set, Iridium. This parameter cannot be changed when the ion gauge is on.Bits 000F0000 Filament NumberIGS_FILNUM_VALID (00080000h). Must be set to write the value. [Cannot be set if ion gauge is on]. IGS_FILNUM _2(00010000h) Filament 2. If this bit is not set, filament 1. This parameter cannot be changed when the ion gauge is on.Bits 000000FF Ion gauge emission/degas settingIGS_EM_VALID (000000FFh). Must be set to write the value.Please see the relevant corresponding section in the Ion Gauge Status parameter for bit/value settings. To change emission,select the desired value, ORing with IGS_EM_AUTO if auto emission is required. To start degas, set to any of the degasvalues, ORed with IGS_EM_QUICKDEGAS if quick degas is required. Whether the degas starts also depends on the setting

for the Degas protection parameter or pressure.[See also Ion Gauge Status 88h]

GROUP 10

144 90h Slot A value 1 32 bit float R SLOT A MEASURED VALUE 1The main measured value for module in Slot A. For example, for Pirani module the pressure, for thermocouple module, thetemperature

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ParameterAddress

ParameterName


146 92h Slot A value 2 32 bit float R SLOT A MEASURED VALUE 2This is reserved for future implementation

148 94h Slot B value 1 32 bit float R SLOT B MEASURED VALUE 1

The main measured value for module in Slot A. For example, for Pirani module the pressure, for thermocouple module, thetemperature

150 96h Slot B value 2 32 bit float R SLOT B MEASURED VALUE 2This is reserved for future implementation

152 98h Heatsinktemperature

32 bit float R HEATSINK TEMPERATUREUsed to control the fan

154 9Ah Ion gaugepressure

32 bit float R ION GAUGE PRESSURERange 1x10-14 to 1x10+3. 1x10+3 returned when ion gauge is off. The values are corrected for the sensitivity factor and arereturned in the selected display units

156 9Ch Ion gaugesensitivity factor

32 bit float R/W ION GAUGE SENSITIVITY FACTORRange: 1.0 to 99.9. IGC3 rounds the value to closest 0.1. Default = 19

158 9Eh Ion gauge lowpass filter

32 bit float R/W ION GAUGE LOW PASS FILTERRange: 0.0 (OFF) to 9.9 seconds. IGC3 rounds value to closest 0.1. Default = 1.5

GROUP 11160 A0h Trip 1 Level 32 bit float R/W TRIP 1 LEVELRange: 1x10-13 to 1x10+6. Units to suit device that trip is allocated to.

162 A2h Trip 2 Level 32 bit float R/W TRIP 2 LEVELRange: 1x10-13 to 1x10+6. Units to suit device that trip is allocated to.




170 AAh Trip 6 Level 32 bit float R/W TRIP 6 LEVELRange: 1x10-13 to 1x10+6. Units to suit device that trip is allocated to.

172 ACh Trip 7 Level 32 bit float R/W TRIP 7 LEVELRange: 1x10-13 to 1x10+6. Units to suit device that trip is allocated to.

174 AEh Trip HysteresisLevel

32 bit float R/W TRIP HYSTERESISRange: 1.0 to 99.0. IGC3 round value to closest 0.1. Default = 1.1x

GROUP 12

176 B0h D/A Output Minvalue

32 bit float R/W MINIMUM D/A SETTINGRange 0 to 4095. Usually set to correspond to 0V output (=~ 20). However, can be made larger than D/A Output Max valueif reverse D/A output action required.

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ParameterAddress

ParameterName


178 B2h D/A Output Maxvalue

32 bit float R/W MAXIMUM D/A SETTINGRange 0 to 4095. Usually set to correspond to 10V output (=~ 4026). However, can be made smaller than D/A Output Minvalue if reverse D/A output action required.

180 B4h D/A MinPressure value

32 bit float R/W D/A MINIMUM Parameter value (pressure or temperature)Range: 1x10-13 to 1x10+6. Units set to the device that D/A is allocated to. Note can be

182 B6h D/A MaxPressure value

32 bit float R/W D/A MAXIMUM Parameter value (pressure or temperature)Range: 1x10-13 to 1x10+6. Units set to the device that D/A is allocated to.

184 B8h D/A Output 32 bit float R/W D/A OUTPUT VALUERange 0 to 4095.Although this parameter can be written to, it should only be written to if the D/A FlagsParameter(5Eh) is set to DA_SET_EXTERNAL.

186 BAh [Unassigned] 32 bit float

188 BCh [Unassigned] 32 bit float

190 BEh Internal 32 bit float R [Reserved for internal use]

GROUP 13

192 C0h Pump DownStart Pressure

32 bit float R/W PUMP DOWN START PRESSURERange: 1x10-13 to 1x10+6. Units to suit device in slot A.

194 C2h Pump DownDelay

32 bit float R/W PUMP DOWN DELAY TIMERange: 0 to 999 seconds

196 C4h Pump Downnum. attempts

32 bit float R/W NUMBER OF ATTEMPTS TO MAKE TO PUMP DOWNRange: 1 to 9

198 C6h [Unassigned] 32 bit float

200 C8h [Unassigned] 32 bit float

202 - CAh Timer pressureLimit

32 bit float R/W PRESSURE LIMIT FOR OPERATION OF ON TIMERange: 1x10-13 to 1x10+6 in currently selected pressure units

204 CCh Timer OFF Time 32 bit float R/W TIMER OFF TIMERange: 0 to 1440 minutes

206 CEh Timer ON Time 32 bit float R/W TIMER ON TIMERange: 0 to 1440 minutes

GROUP 14208 D0h Bake-out Temp 1 32 bit float R/W BAKE-OUT TEMPERATURE FOR STEP 1

Range: 0 to 600C

210 D2h Bake-out Temp 2 32 bit float R/W BAKE-OUT TEMPERATURE FOR STEP 2Range: 0 to 600C

212 D4h Bake-out Temp 3 32 bit float R/W BAKE-OUT TEMPERATURE FOR STEP 3

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ParameterAddress

ParameterName


Range: 0 to 600C

214 D6h Bake-out Temp 4 32 bit float R/W BAKE-OUT TEMPERATURE FOR STEP 4Range: 0 to 600C

216 D8h Bake-out Temp 5 32 bit float R/W BAKE-OUT TEMPERATURE FOR STEP 5Range: 0 to 600C218 - DAh Bake-out Temp 6 32 bit float R/W BAKE-OUT TEMPERATURE FOR STEP 6

Range: 0 to 600C

220 DCh Bake-out TempHysteresis

32 bit float R/W HYSTERESIS APPLIED TO BAKE-OUT TEMPERATURERange: 0 to 99C

222 DEh Bake-outPressure Limit

32 bit float R/W BAKE-OUT PRESSURE LIMITRange: 1x10-13 to 1x10+6 in currently selected pressure units

GROUP 15

224 E0h Bake-out Time 1 32 bit float R/W BAKE-OUT TIME FOR STEP 1Range: 0 to 99.9 hours





234 - EAh Bake-out Time 6 32 bit float R/W BAKE-OUT TIME FOR STEP 6Range: 0 to 99.9 hours

236 ECh Bake-outSetpoint

32 bit float R CURRENT BAKE-OUT TEMPERATURE SET-POINTRange: 0 to 600C.Note this is the required temperature. The actual measured temperature is available from Parameter Slot BMeasured 1 (i.e. the thermocouple module in Slot B)

238 EEh Remaining bake-out time

32 bit float R TOTAL REMAINING BAKE-OUT TIMERange: 0 to 599.4 hours

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