Woodward 2301D, Инструкция по установке и эксплуатации, Страница: 110 / 130

2301D/2301D-EC Digital Control Manual 26247
102 Woodward
2301D Control Modbus Addresses
The Modbus communication ports in the 2301D are programmed for unique
Modbus addresses. A complete listing of these addresses for your application is
located at the end of this section in the manual. The Modbus address listing
consists of Boolean Writes, Boolean Reads, Analog Reads and Analog Writes.
All values that can be addressed by Modbus are considered to be discrete and
analog. The discrete values are a 1 bit binary, on or off value, and the analogs
are 16 bit values. All read/write registers are interpreted by the 2301D as signed
16 bit integer values. Since Modbus can only handle integers, values that require
a decimal point in the Modbus Master Device are multiplied by a scaling constant
before being sent by the 2301D. See Appendix B for the default communication
constants and ranges.
Boolean Writes
Boolean Writes are logic signals that are writable to the 2301D control. An
example of a Boolean write value would be raise or lower commands. A logical
true denoted by the value 1 will cause the command listed in the description to
be executed.
If a RUN (address 0.0002) command is given it will be latched. To reset the latch
remove the RUN contact and give a command to STOP (address 0.0003). This is
applicable for the following commands:
0.0002
Run (latch)
0.0003 Stop (reset latch)
0.0004 Failed Speed Override ON (latched)
0.0005 Failed Speed Override OFF (reset latch)
0.0006
Rated (latched)
0.0007 Idle (reset latch)
0.0010 Isoch (latched)
0.0011 Droop (reset latch)
0.0012 Baseload ON (latched)
0.0013 Baseload OFF (reset latch)
Boolean Reads
Boolean Reads are logic signals that are readable from, but not writable to, the
2301D. An example of a Boolean read value would be a turbine trip status
indication. The logic true will have the value 1 if the statement in the description
column is true and a 0 if false. The ‘1:’ term in the address identifies a logic true.
The 2301D supports Modbus function code 2, which involves reading selected
logic signals.