Teledyne 6712FR and, Installation And Operation Manual, Page: 146 / 244

6712FR Refrigerated Sampler
Section 7 Remote Operation
7-4
7.1.2 External Program
Control
Under external program control, the sampler operates 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 (for
SCADA or other systems) that directs sample collection
according a system’s needs.
The 6712 controller will respond to four commands:
• Turn on the sampler
• Take a sample
• Send status
• Send data
Note that commands and responses are comma-separated pairs.
The first set of alpha-characters is an identifier; the second set of
numeric characters indicates the value. The 6712 controller will
not receive and process the command unless it is followed by a
carriage return.
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 and return status is:
STS,2
<CR>
Take a Sample – This directs the sampler to take a sample. The
command specifies how much volume to take, and which bottle to
place the sample in. The sampler responds by taking a sample
and returning a status string that reports the new status.
An example of a command to take a sample is shown below:
BTL,2,SVO,100
<CR>
This example instructs the sampler to place the distributor arm
over bottle 2 (
BTL,2
) and take a 100 ml sample (
SVO,100
).
While most settings of the sampler program (start times,
enables, distribution schemes, etc.) are ignored when responding
to external commands, the sampler does rely on two program set-
tings that “configure” the sampler. These settings are:
• Number of Bottles–is used to determine the distributor
arm position and the acceptable range for the
BTL
values.
• Suction Line Length–Used with liquid detection to
deliver correct sample volumes according to the
SVO
value.