Coil Register Addressing - Danfoss VLT AutomationDrive FC 300 Design Manual

RS-485 Installation and Set...

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
1–16 Adjustable frequency drive control word (see Table 10.13)
17–32 Adjustable frequency drive speed or setpoint reference Range 0x0–0xFFFF
(-200% ... ~200%)
33–48 Adjustable frequency drive status word (see Table 10.13)
49–64 Open-loop mode: Adjustable frequency drive output frequency Closed-loop
mode: Adjustable frequency drive feedback signal
65 Parameter write control (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
01 Preset reference LSB
02 Preset reference MSB
03 DC brake
04 Coast stop
05 Quick stop
06 Freeze freq.
07 Ramp stop
08 No reset
09 No jog
10 Ramp 1
11 Data not valid
12 Relay 1 off
13 Relay 2 off
14 Set up LSB
15 Set up MSB
16 No reversing
Table 10.13 Adjustable Frequency Drive Control Word (FC Profile)
MG34S222
Design Guide
1
No DC brake
No coast stop
No quick stop
No freeze freq.
Start
Reset
Jog
Ramp 2
Data valid
Relay 1 on
Relay 2 on
Reversing
Danfoss A/S © Rev. 2014-02-10 All rights reserved.
Signal direction
Master to follower
Master to follower
Follower to master
Follower to master
Master to follower
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