Danfoss VLT Flow Drive FC 111 Design Manual page 114

VLT® Flow Drive FC 111
Design Guide
implementation, the low-order byte of the field is appended first, followed by the high-order byte. The CRC high-order byte is the
last byte sent in the telegram.
8.8.8 Coil Register Addressing
8.8.8.1 Introduction
In Modbus, all data is organized in coils and holding registers. Coils hold a single bit, whereas holding registers hold a 2 byte word
(that is 16 bits). All data addresses in Modbus telegrams are referenced to 0. The 1
number 0. 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 telegram. 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 telegram. The function code field already speci-
fies a holding register operation. Therefore, the 4XXXX reference is implicit. Holding register 40108 is addressed as register 006Bhex
(107 decimal).
8.8.8.2 Coil Register
Table 63: Coil Register
Coil number Description
1–16 Drive control word.
17–32 Drive speed or setpoint reference range 0x0– 0xFFFF (-200% ... ~200%).
33–48 Drive status word.
49–64
Open-loop mode: Drive output frequency.
Closed-loop mode: Drive feedback signal.
65 Parameter write control (master to follower).
0 = Parameter changes are written to the RAM of the drive.
1 = Parameter changes are written to the RAM and EEPROM of the drive.
66–65536 Reserved.
8.8.8.3 Drive Control Word (FC Profile)
Table 64: Drive Control Word (FC Profile)
Coil 0
01 Preset reference lsb
02 Preset reference msb
03 DC brake
04 Coast stop
05 Quick stop
06 Freeze frequency
07 Ramp stop
08 No reset
09 No jog
10 Ramp 1
114 | Danfoss A/S © 2021.04
RS485 Installation and Set-up
st
occurrence of a data item is addressed as item
1
No DC brake
No coast stop
No quick stop
No freeze frequency
Start
Reset
Jog
Ramp 2
AJ363928382091en-000101 / 130R0983
Signal direction
Master to follower
Master to follower
Follower to master
Follower to master
Master to follower
–