Teledyne 6712SR, Installation And Operation Manual

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6712SR Refrigereated Sampler
Section 7 Remote Operation
7-3
Note
You can retrieve the sampling reports at any time using the
same serial connection. Type “Q” to exit the menu. Then at the
> prompt, type “REPORT” and press Enter. The sampler con-
troller will send reports as configured.
7.1.2 External Program
Control
Under external program control, the pump and distributor
operate according to received commands. An external program
can be as simple as manually-entered commands to collect a
sample when needed, or as complex as a user-developed process
control program that directs sample collection according a
system’s needs.
The 6712 controller will respond to four commands:
Turn on the sampler – If the sampler is OFF, the sampler
responds by placing itself in the ON state and returning a status
string to report the new status. (See
Send Status for a
description of this string.)
The command to turn the sampler ON is:
STS,2
Note that commands and responses are comma-separated pairs.
The first set of alpha-characters are an identifier; the second set
of numeric characters indicate the value. The 6712 controller will
not receive and process the command unless it is followed by a
carriage return.
Checksum optional Optionally, commands to the sampler can be validated using a
checksum. Checksum validation can avoid problems caused by
faulty program control or communication lines. When using the
checksum, add the CS identifier and a comma at the end of the
command. and the checksum value of the string up to the last
comma. For example, the command with checksum validation to
turn the sampler on would appear as:
STS,2,CS,582
The numeric value of each character is its ASCII equivalent
expressed in decimal format. The checksum of “582” was calcu-
lated as shown below.
STS,2,CS,582
83
84
83
44
50
44
67
83
44
582