Chapter 9 green series communications – Yokogawa Data Acquisition with PID Control CX2000 User Manual
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9-1
IM 04L31A01-17E
9
Green Series Communications
9.1
Specifications of the Green Series
Communication Function
Communication Protocol
MODBUS communication RTU mode
Connecting Model (Controller)
• UT Series (UT320, UT321, UT350, UT351, UT420, UT450, UT520, UT550, and
UT750 are applicable. However, if using “heating/cooling control” or “custom
computation control” on the UT series, “ETC” is set on the selection menu.)
• Devices other than above that have the MODBUS slave function (selection menu
shows “ETC” for these devices.)
Supported functions vary depending on the model.
Number of Connectable Loops
16 loops (4 loops on the CX1000)
Read Cycle
• Same as the read cycle of the Modbus master function.
• If you are using the UT series indicated above, a read cycle of 1 s is recommended
for every 4 loops connected. However, communications with the UT320, UT321,
UT350, and UT351 takes twice the amount of time as with other UT series
instruments, therefore a read cycle of 2 s is recommended when using the UT320,
UT321, UT350, or UT351 with 4 loops connected.
Function
Supported functions vary depending on the connecting model.
• When the connecting model is UT Series
1.
Monitor and record PV, SP, and OUT values on the measurement display
(such as the trend display).
2.
Monitor the PV, SP, and OUT values on the control group display and control
overview display.
3.
Monitor the control operation (AUT/MAN/CAS, LOCAL/REMOTE, RUN/STOP,
and alarm status) on the control group display or control overview display.
4.
Monitor and record alarm information using the alarm summary function.
5.
Monitor and record the control operation (AUT/MAN/CAS, LOCAL/REMOTE,
and RUN/STOP) using the control summary function.
6.
Monitor and change the PID parameters of each loop on the tuning display.
7.
Change the SP value.
8.
Change the OUT value in manual mode.
9.
Switch AUTO/MAN.
10. Switch RUN/STOP.
11. Switch LOCAL/REMOTE.
12. Execute auto tuning.
13. Switch the SP number.
14. Automatic retrieval of various setup information of the controller
CX2000: Auto reading possible on the External loop setting (Basic setting)
display that appears by selecting “Basic Setting mode > [#10] (Control) > [#6]
(External loop setting) > [#1] (Basic setting)”).
CX1000: Auto reading possible on the Basic setting display that appears by
selecting “Basic Setting mode > [#12] (Control) > [#8] (External loop setting) >
[#1] (Basic setting)”).
• When the connecting model is “ETC”
Supports only the functions of 1, 2, and 5 above.
Chapter 9 Green Series Communications