Yokogawa GC8000 Process Gas Chromatograph - Manual (Page 466)

<Appendix D Action of External Input and Output Signals>
App.D-21
IM 11B08A01-01E
  Serial Communication (Y-Protocol)
The GC8000 uses two types of serial communications: DCS and GCCU. The protocol of DCS
communication is classifi ed into MODBUS and Y-Protocol (GC1000/GC8, GC6 and BTU for
Japan).
The settings for Y-Protocol are described below. For the serial communication settings, see
“5.4.14 Communications Setup.”
For the data specifi cations in the MODBUS communication, see GS 11B08B02-01E.
The GC8000 supports Y-Protocol only when both GCM and SYS are a single confi guration.
The settings for Y-Protocol on the serial communication setting screen are shown below.
● Trans contents
Analyzed value: Sends analysis value and calibration factor data, not alarm data.
Alarm: Sends alarm data, not analysis value and calibration factor data.
All data: Sends analysis value, calibration factor, and alarm data.
● Recep contents
None: Accepts no input data.
Command: Accepts no input data.
All data:
Accepts no input data.
GC8 type: Accepts input data after sending analysis value or other data. The GC8000
normally accepts input data every 7 to 8 seconds.
● Procedure
Without procedure: Upon outputting analysis value, calibration factor, or alarm data, the
GC8000 sends the relevant data packet to DCS. The GC8000 sends the packet only once.
With precedure: Upon outputting analysis value, calibration factor, or alarm data, the
GC8000 sends an output command packet to DCS.
After receiving the output command packet, DCS sends an input command packet back to
the GC8000 as necessary.
After receiving the input command packet, the GC8000 sends the relevant data packet to
DCS.
For the detail, see “ In the case of “with procedure”” in page of App.D-26 .
 Communication Data
The types of communication data for Y-Protocol are as follows:
(1) Analysis value data (GC8000 to DCS)
After the calculation, the GC8000 outputs analysis value data.
(2) Calibration factor (GC8000 to DCS)
After the calculation, the GC8000 outputs calibration factor data.
(3) Error alarm (GC8000 to DCS)
When an alarm occurs, the GC8000 outputs alarm data.
(4) Input data (DCS to GC8000)
The GC8000 receives various commands including the Run command.
TIP
Indication in the packet
CR: Carriage return
LF: Line feed
A dummy space is indicated in gray.
2nd Edition : May 11, 2012-00
App.D