Teledyne 6712SR - Manual (Page 130)

6712SR Refrigerated Sampler
Section 5 Extended Programming
5-42
For more consistent sample volumes from lines under constant
pressure, calibrate the samples. Teledyne Isco does not rec-
ommend sampling from pressurized lines.
5.22 Command Driven
Operation
The 6712 controller can be used as a slave to an external con-
troller. The external controller is responsible for determining
when to take a sample, how much volume to pump, and where to
put the sample. The external controller directly interfaces to the
sampler via an RS-232 communications port at 2,400-19,200
baud, 8 data bits, no parity, and 1 stop bit. A comma-sepa-
rated-value protocol is used by the external controller to make
requests, and by the sampler to report results. Use a standard
computer connect cable (see Appendix E) to connect the sampler’s
interrogator port and the external controller.
For information on serial data codes and their meanings, refer to
Table 5-5 Serial Data Codes in this section.
The 6712 Sampler will respond to three commands: Turn
Sampler On, GET STATUS, and TAKE SAMPLE. All commands
must include the instruction set. The checksum value is optional.
The available commands are:
1. Turn Sampler On: STS,2,CS,582<CR>
• “582” is the byte-by-byte sum of the ASCII values in the
string “STS, 1,CS”.
• “<CR>” is a carriage return signifying the end of the
command.
• If the sampler is OFF, this command will turn it ON
before returning status info.
2. Get Status: STS,1,CS,581<CR>
“STS,1” instructs the sampler to return the current status.
• “CS,581” is the optional checksum value. The
byte-by-byte sum of the ASCII values in the string
“STS,1,CS” is 581.
• “<CR>” is a carriage return signifying the end of the
command.
3. Take Sample: BTL,2,SVO,100,CS,1039<CR>
The TAKE SAMPLE command is only valid if the sampler is
WAITING TO SAMPLE.
• “BTL,2” instructs the sampler to place the sample in
bottle 2.
• “SVO,100” instructs the sampler to take a 100 ml
sample.
• “CS,1039” is the optional checksum value. The
byte-by-byte sum of the ASCII values in the string
“BTL,2,SVO,100,CS,” is 1039.
• “<CR>” is a carriage return signifying the end of the
command.