Teledyne manual 6712FR Refrigerated Sampler, Section, Remote Operation, 7.1.2, External Program

6712FR Refrigerated Sampler
Section 7	Remote Operation
7.1.2	External Program	Under external program control, the sampler operates according
	Control	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.

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