Teledyne 6000B Operating Instructions Manual page 22

2 Installation
Digital Remote Cal Inputs
Remote Zero and Span Inputs: The REMOTE SPAN and RE-
MOTE ZERO inputs are on the DIGITAL INPUT terminal block. They
accept 0 V (OFF) or 24 V dc (ON) for remote control of calibration (See
Remote Calibration Protocol below.)
Zero: Floating input. 5 to 24 V input across the + and – terminals
puts the analyzer into the ZERO mode. Either side may be
grounded at the source of the signal. 0 to 1 volt across the
terminals allows ZERO mode to terminate when done. A
synchronous signal must open and close the external zero
valve appropriately. See Remote Probe Connector at end of
section 3.3. (With the -C option, the internal valves automati-
cally operate synchronously).
Span: Floating input. 5 to 24 V input across the + and – terminals
puts the analyzer into the SPAN mode. Either side may be
grounded at the source of the signal. 0 to 1 volt across the
terminals allows SPAN mode to terminate when done. A
synchronous signal must open and close the external span
valve appropriately. See Remote Probe Connector at end of
section 3.3. (With the -C option, the internal valves automati-
cally operate synchronously.)
Cal Contact: This relay contact is closed while analyzer is spanning
and/or zeroing. (See Remote Calibration Protocol below.)
Remote Calibration Protocol: To properly time the Digital Remote
Cal Inputs to the Model 6000B 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:
2-8: Part I
To reset a System Alarm during installation, discon-
nect power to the instrument and then reconnect it
Further detail can be found in chapter 3, section 4-5.
Teledyne Analytical Instruments
Model 6000B