INFICON SQC-122 User Manual

Sigma

instruments

?

1318 Duff Drive ? Fort Collins, Colorado 80524 ? [phone] ? Fax [phone]

Communications with the SQC-122

There are three possibilities for communicating with the SQC-122. The first is a DOS­based terminal program. The next is a 32 bit Windows DLL. The third is a Windows
program that can configure and operate the SQC-122.

SQM-TERM.EXE

This simple DOS-based terminal program allows you to send a command and receive a
response via the computer’s RS-232 port. The computer’s COM1 port baud rate must
be set to match the SQC-122 before the program is run. Source code (SQM-TERM.C)
is provided, so it can be customized easily. The command and response strings are
detailed in the attached Communications Protocol.

SIGMACOM.DLL

This 32 bit DLL should be placed in your Windows System directory. No Windows
registration is needed. The first call should be to InitCom to establish the comm port and
baud rate. Functions and their calling convention are listed in the attached
SIGMACOM.DLL Functions document.

SQC-122.EXE

This program uses SIGMACOM.DLL to communicate with the SQC-122. It must be
installed in Windows using the Setup SQC-122 installation program. It allows you to set
film parameters and names, download them to the SQC-122, and perform front panel
functions. This program is written in Visual Basic, contact Sigma Instruments if you need
the source code for this program.

Sigma

instruments

?

1318 Duff Drive ? Fort Collins, Colorado 80524 ? [phone] ? Fax [phone]

SQC-122 Communications Protocol

The SQC-122 communicates with a host computer via an ASCII based protocol. The
instrument defaults to 19200 baud, 8 data bits, and no parity. The baud rate can be
changed in the System Menu of the SQC-122, but is always 8 data bits with no parity.

The basic protocol is:

<sync character> <length character> <1 to n data characters> <CRC1><CRC2>

Once a valid command has been transmitted to the SQC-122, a response is returned.
The structure of the packet is identical in both the command and response. In the
response, the first character is a Response Status. These are summarized in the
following table.

Response Letter Meaning

A Command understood, normal response
B Command understood, but instrument reset
C Invalid command
D Problem with data in command
E Instrument in wrong mode for this command

The sync character is an exclamation point ‘!’. Anytime this character is received, the
communications for that packet is reset. Following the sync character is the length
character. This is the number of characters in the packet starting with the length and
counting the 2 CRC characters. This character has a decimal 34 added to it so there
cannot accidentally be a sync character embedded in the packet. The two character
CRC is computed using the following algorithm:

1. The CRC is initialized to 3FFF hex.

2. Each character in the message is examined, bit by bit, and added to the CRC
in the following manner:

a) The character is exclusive or’d with the CRC.
b) The CRC is shifted right one bit position.
c) If the character’s least significant bit is a 0 then the CRC is exclusive or’d

with 2001 hex.

d) Steps b and c are repeated for each of the 8 bits in the character.

The CRC contains 14 significant bits. This is split into two characters of 7 bits each, and
then a decimal 34 is added to offset the character outside the range of the Sync

Sigma

instruments

?

1318 Duff Drive ? Fort Collins, Colorado 80524 ? [phone] ? Fax [phone]

Character. See the code example in the SQM-TERM.C file for an example of managing
the CRC.

These examples represent the data in unpacked format to better illustrate the function of
the specific commands.

Command: @
Parameters: None
Description: Returns the model number and software version number.
Example: @ SQC122 Ver 1.2

Command: L
Parameters: [1..2]
Description: Read the current Rate for a channel.
Example: L1 A9.32 Channel one’s rate is 9.32 Angstroms/S

Command: M
Parameters: None.
Description: Read the current Average Rate.
Example: M A10.42 Average Rate is 10.42 Angstroms/S

Command: N
Parameters: [1..2]
Description: Read the current thickness for a channel.
Example: N2 A1.187 Channel two’s Thickness is 1.187 Kilo Angstroms.

Sigma

instruments

?

1318 Duff Drive ? Fort Collins, Colorado 80524 ? [phone] ? Fax [phone]

Command: O
Parameters: None.
Description: Read the current Average Thickness
Example: O A2.376 The current Average Thickness is 2.376 kilo

Angstroms.

Command: P
Parameters: [1..2
Description: Read the current Frequency for a channel.
Example: P2 A5701563.2 Channel two’s current Frequency 5701563.2Hz

Command: R
Parameters: [1..2]
Description: Read the Crystal Life for a channel.
Example: R2 A57.82 Channel two’s remaining life is 57.82%.

Command: S
Parameters: None.
Description: Zero Average Thickness and Rate.
Example: S A

Command: T
Parameters: None.
Description: Zero Time

Sigma

instruments

?

1318 Duff Drive ? Fort Collins, Colorado 80524 ? [phone] ? Fax [phone]

Example: T A Zeroes time display on unit.

Command: U
Parameters: 0 to 33
Description: Controls operation of the SQC-122.

0 = Start Process 6 = Start Process 1
1 = Stop Process 7 = Start Process 2
2 = Start Layer 8-30 = Start Process 3-25
3 = Stop Layer 31 = Soak Hold
4 = Start Next Layer 32 = Zero Thickness
5 = Force Final Thickness 33 = Zero Time

Example: U1 A Starts the first layer of the active process.

Command: V
Parameters: None
Description: Controls operation of the SQC-122.

0 = Stopped 8 = Soak 2 16 = Start Next Layer
1 = Crystal Verify 9 = Soak Hold 17 = Crystal Fail
2 = Initialize layer 10 = Shutter Delay 18 = Stop Layer
3 = Manual Start Layer 11 = Deposit 19 = Manual Power
4 = Pocket Rotate 12 = Rate Ramp
5 = Ramp 1 13 = Rate Ramp Deposit
6 = Soak 1 14 = Timed Power
7 = Ramp 2 15 = Idle Ramp

Example: U1 A9 Units is in Soak Hold phase.

Command: Y
Parameters: None.
Description: Read the Power-Up Reset flag. The Power-Up Reset flag is set during

boot-up of the unit and stays set until read through the RS-232 interface.

Sigma

instruments

?

1318 Duff Drive ? Fort Collins, Colorado 80524 ? [phone] ? Fax [phone]

After the flag is read, it is reset and will not be set again until the unit is
power cycled.

Example: Y A1 Power-Up Reset flag is set.

Y A0 Power-Up Reset flag is reset.

Command: Z
Parameters: None.
Description: Set all Film and System parameters to defaults.

Note that this command can take over 1 second to complete

Example: Z A All Film and System parameters are set to defaults.

Sigma

instruments

?

1318 Duff Drive ? Fort Collins, Colorado 80524 ? [phone] ? Fax [phone]

SIGMACOM.DLL Function Descriptions

This dll acts as an interpreter between an application and the SQC122. The dll

transforms function calls to specific command sequences that the unit understands.

Transfer of data to the unit, in general, requires two function calls. The first
function call is to transfer the data to the unit. The data to be sent is usually contained in
the function’s parameter(s). The second function call is to ChkCommDone. This function
call ensures that the data was sent properly to the unit.

Data retrieval requires three function calls. The first function call is used to tell the
unit what data is being requested. The second function call is to ChkCommDone. This
function call is used to determine when all of the data has been transferred from the unit
to the dll or if an error occurred in the communications. The third function call is used to
retrieve the data from the dll.

InitComm

Parameters: 16 Bit Integer, 32 Bit Integer

Return : 16 Bit Integer.

InitComm is used to initialize the dll com port. The function’s first parameter is the

com port number to initialize (1 - 99 are valid). The second parameter is the baud

rate for the port. The function returns zero if initialization was successful or a bit

flag to indicate the failure of the initialization :

Example:

bit 0 : Communications Port handle is invalid.
bit 1 : Communications Port Set parameters invalid (Baud Rate)
bit 2 : Communications Port Set timeouts invalid.
bit 3 : Communications Port Set mask invalid.
bit 4 : Communications Port Error – Already exists.
bit 5 : Communications Port Set Read Thread fail.
bit 6 : Communications Port Set Read Thread priority fail.

ReturnVal =InitComm(1,19200) initialize Com1 to 19200 baud
if (ReturnVal != 0) if port did not initialize correctly
CloseComm() close the port