6700SR Refrigerated Sampler
99
Command Driven Operation
The 6700SR controller can be placed in a mode where it is a slave
to an external controller. 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 inter-
faces to the sampler via an RS-232 communications port at 2400
baud, 8 data bits, no parity, and 1 stop bit. A comma-separated-val-
ue 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.
To enable the command driven mode, press at the
main menu. The sampler then displays its current command driv-
en state (normally WAITING TO SAMPLE) and is ready to respond
to valid commands from the external controller. From the WAIT-
ING TO SAMPLE screen, press the (Stop) key to check the sam-
pler setup (screen 61). To change the setup, use the arrow keys to
select the item to modify, and press enter. Select DONE to save the
changes and return to command driven operation.
To return to normal sampler operation, press for
standard programming or for extended program-
ming while at the sampler setup screen (screen 61).
While in the command driven mode the sampler will be quite lim-
ited in its functionality. Some of the limitations are:
•No modules
• No partition data
• No sample event log
• No reports
• No Flowlink communication
• No programmable I/O
• No sample calibration
• No rinses or retries
• Auto suction head (head based on line fill counts and line length)
• Purge times become a function of the line length
• Event is sent during the entire pump cycle.
The 6700SR Sampler will respond to three commands: GET STA-
TUS, TAKE SAMPLE, and SET TIME. All commands must include
the instruction set and a checksum value.
Get Status
There is only one form of this command available:
STS,1,CS,581<CR>
•“STS,1” instructs the sampler to return the current status
•“CS,581” is the 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.
Command Driven Mode
Charts showing the Command Driv-
en screens appear in
Figure 46
,
Command Driven Screens
on page
129.
61
__ ft SUCTION LINE
__ BOTTLES
PUMP TUBE ALARM
DONE
6 7 0 0 . 3
6 7 0 0 . 1
6 7 0 0 . 2
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