Yokogawa GC8000 Process Gas Chromatograph - Manual (Page 472)

<Appendix D Action of External Input and Output Signals>
App.D-27
IM 11B08A01-01E
● Answerback (command not executed) (#W or #W#)
1 2 3 4 When receiving an invalid-format command 1 2 3 4 5
# W CR LF # W # CR LF
TIP
Answerback (comannd not executed) #W and #W#
#W: When the command includes an out-of-range parameter
When sending a message to another task has failed
#W#: Invalid format
Invalid command length
Undefi ned command
Invalid analyzer ID for the GC1000/GC8
Input instruction (DCS to GC8000)
● Data transmission request (#A)
1 2 3 4
# A CR LF
● Data retransmission request (#R)
1 2 3 4
# R CR LF
● Example of communication “with procedure”
The GC8000 sends “Input command prompt (#T)” at an interval of 8 seconds.
<When any data of analysis value, calibration factor or alarm is communicated.>
In the case of “with procedure” and upon outputting analysis value (concentration/calculation),
calibration factor, or alarm data, the GC8000 issues the relevant data packet to DCS by the
following procedure.
● Normal comminucation
(1) When the GC8000 is ready to send data to DCS, the GC8000 fi rst sends “Data receiving
request (#E)” to DCS.
(2) Upon receiving “Data transmission request (#A)” from DCS, the GC8000 sends all data.
After the completion, the GC8000 sends “Data transmission completion (#F).”
*1
*2 *2
DCS #A #A - - - - #A
GC8000 #E Data 1 - - - - - Data n #F
*1: 3 seconds or less, *2: 0.04 seconds
● When not receiving “Data transmission request (#A or #R)”
If the GC8000 does not receive “Data transmission request (#A or #R)” from DCS for about
3 seconds after sending “Data receiving request (#E)”, the GC8000 sends “Data receiving
request (#E)” again. The GC8000 repeats the same request up to six times (7 times in total)
until the GC8000 receives a reply from DCS. If it does not receive any reply, the GC8000
sends “Data transmission completion (#F)” to DCS.
*1 *1
DCS
GC8000 #E #E #E #E #E #E #E #F
*1: 3 seconds
2nd Edition : May 11, 2012-00
App.D