Teledyne 7300a - NDIR analyzer - Manual (Page 20)

2 Installation Model 7300A
2-8 Teledyne Analytical Instruments
Table 2-6: Remote Calibration Connections
Pin Function
9 + Remote Zero
11 – Remote Zero
10 + Remote Span
12 – Remote Span
40 Cal Contact
41 Cal Contact
Remote Calibration Protocol: To properly time the Digital Remote
Cal Inputs to the Model 7300A Analyzer, the customer's controller must
monitor the Cal Relay Contact.
When the contact is OPEN, the analyzer is analyzing, the Remote Cal
Inputs are being polled, and a zero or span command can be sent.
When the contact is CLOSED, the analyzer is already calibrating. It
will ignore your request to calibrate, and it will not remember that request.
Once a zero or span command is sent, and acknowledged (contact
closes), release it. If the command is continued until after the zero or span is
complete, the calibration will repeat and the Cal Relay Contact (CRC) will
close again.
For example:
1) Test the CRC. When the CRC is open, Send a zero command
until the CRC closes (The CRC will close quickly.)
2) When the CRC closes, remove the zero command.
3) When CRC opens again, send a span command until the CRC
closes. (The CRC will close quickly.)
4) When the CRC closes, remove the span command.
When CRC opens again, zero and span are done, and the sample is
being analyzed.
Note: The Remote Probe connector provides signals to operate the
zero and span gas valves synchronously. However, if you
have the –C Internal valve option, which includes zero and
span gas inputs, the 7300A automatically regulates the zero,
span and sample gas flow.