Installation BDS 3960
Teledyne Analytical Instruments 38
W h e n t h e c o n t a c t i s OP E N , t h e an a l y z e r i s an a l y z i n g , t h e
R e m o t e Ca l I n p u t s ar e be i n g po l l e d , an d a ze r o or sp a n co m m a n d
c a n be se n t .
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 quickly close.)
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 quickly close.)
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 Valve connections (described below) provides
signals to ensure that the zero and span gas valves will be
controlled synchronously.
Range ID Relays: There are four dedicated Range ID relay contacts.
The first three ranges are assigned to relays in ascending order—Low
range is assigned to Range 1 ID, Medium range is assigned to Range 2
ID, and High range is assigned to Range 3 ID. The fourth range is
reserved for the over Range (100 ppm). Table 3-4 lists the pin
connections. There is contact opening to indicate what range the
analyzer is on. The contacts open when the analyzer is on that range.