Yokogawa GC8000 Process Gas Chromatograph - Manual (Page 446)

App.D-1
IM 11B08A01-01E
Appendix D Action of External Input and
Output Signals
 Analog output
There are two types of analog output. The maximum number of outputs depends on the type of
outputs.
Analog hold output Output of analysis results
Up to 32 outputs (8 per card)
The output range can be arbitrarily set within the measurement range.
Note: cannot coexist with GCCU-MarkII (serial) communication.
Chromatogram output Output of chromatograms
Up to 8 outputs
The same detector number can be assigned to multiple A/Os.
The auto gain and auto zero can be set for each detector.
Note: can coexist with GCCU-MarkII (serial) communication.
(1) Analog Hold Output
This is a function to output analysis results as A/O.
The A/O range can be arbitrarily set within the measurement range in the individual peak setting
by using partial settings.
Some partial settings of the measurement range and A/O values are shown in Table 1.
Table 1
Individual peak setting A/O range
Concentration
(ppm)
A/O value
Stream
- peak
Measurement
range (ppm)
Partial setting Concentration
(ppm)
Current
(mA)
Voltage
(V)
Current
(mA)
Voltage
(V)
#1-#1 1000
1.000 1000.000 20 5
800.000 16.8 4.2
0.000 0.000 4 1
#2-#1 1000
0.800 900.000 20 5
800.000 14.7 3.7
0.500 600.000 4 1
* Voltage of 1 to 5 V is converted from electric current of 4 to 20 mA using a 250-ohm shunt resistor.
In setting the analog hold output, the number of output analysis values and output actions are
different when an actual stream is set and when “99” is set for the output stream number. Actions
of contact output are different whether a contact output is used or not as a stream identifi cation
signal.
Analog hold output When an actual stream number is set for
the output stream number, up to 2 analysis
values (different streams) are output.
Without a stream identifi cation signal
With a stream identifi cation signal
When “99” is set for the output stream
number, an analysis value is output for every
stream that belongs to the GCM.
With a stream identifi cation signal
(No other option)
A stream identifi cation signal is a binary-coded stream number which is encoded by turning on
and off multiple contact outputs. To use the stream identifi cation signal as a stream identifi cation
fl ag, which informs upper systems of the update of A/O, as many D/Os as the streams are
required to be initially prepared.
For calibration (or validation) streams, the stream identifi cation signal output is initially set to
“Exist” or “None.” It is set to “Exist” at shipment unless otherwise specifi ed.
• Output exists for calibration (or validation)
• No output for calibration (or validation):
2nd Edition : May 11, 2012-00
App.D