10.11.8 Coil Register Addressing
In Modbus, all data are organized in coils and holding registers. Coils hold a single bit, whereas holding registers hold a 2-
byte word (16 bits). All data addresses in Modbus messages are referenced to zero. The first occurrence of a data item is
addressed as item number zero. For example: The coil known as ‘coil 1’ in a programmable controller is addressed as coil
0000 in the data address field of a Modbus message. Coil 127 decimal is addressed as coil 007EHEX (126 decimal).
Holding register 40001 is addressed as register 0000 in the data address field of the message. The function code field
already specifies a ‘holding register’ operation. Therefore, the ‘4XXXX’ reference is implicit. Holding register 40108 is
addressed as register 006BHEX (107 decimal).
Coil number
Description
Signal direction
1–16
Adjustable frequency drive control word (see
Master to follower
17–32
Adjustable frequency drive speed or setpoint reference Range 0x0–0xFFFF
(-200% ... ~200%)
Master to follower
33–48
Adjustable frequency drive status word (see
Follower to master
49–64
Open-loop mode: Adjustable frequency drive output frequency Closed-loop
mode: Adjustable frequency drive feedback signal
Follower to master
65
Parameter write control (master to follower)
Master to follower
0 = Parameter changes are written to the RAM of the adjustable frequency drive
1 =Parameter changes are written to the RAM and EEPROM of the adjustable
frequency drive.
66-65536
Reserved
Table 10.12 Coils and Holding Registers
Coil
0
1
01
Preset reference LSB
02
Preset reference MSB
03
DC brake
No DC brake
04
Coast stop
No coast stop
05
Quick stop
No quick stop
06
Freeze freq.
No freeze freq.
07
Ramp stop
Start
08
No reset
Reset
09
No jog
Jog
10
Ramp 1
Ramp 2
11
Data not valid
Data valid
12
Relay 1 off
Relay 1 on
13
Relay 2 off
Relay 2 on
14
Set up LSB
15
Set up MSB
16
No reversing
Reversing
Table 10.13 Adjustable Frequency Drive Control Word (FC Profile)
RS-485 Installation and Set...
Design Guide
MG34S222
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Содержание VLT AutomationDrive FC 300
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