NFO
Drives
AB
2021
201013
‐
2
Operating
and
Installation
Manual
41
Default bus master access to Modbus register addresses should be by using the ADI base register address (i.e. a
register address that is a multiple of 4). The bus master may also choose to access the registers that are located
on the “in-between addresses” (e.g. 211h, 212h and 213h), but this will only be possible if the parameter in
question is 32-bit (or 2x 32-bit, 4x 16-bit, etc), and if the parameter itself requires explicit access to a register
address that is not aligned with the ADI base address. If bus master makes an illegal register address access, the
inverter will reply with a Modbus error code.
For bus master read access, the number of registers to read in each transmission is internally limited to the number
of registers used by the ADI in question, i.e. maximum four consecutive registers (if parameter is 64 bits).
Below follows a selection of parameters that can be accessed from the inverter. A complete list of parameters can
be downloaded from www.nfodrives.se
Parameter Name
ADI Modbus reg. addr
Type
Scaling/ Coding
Remark
I-rms (output current)
120 03ECh – 03EDh
SINT32 mA (A × 10
3
) Read
only
P-out (output power)
121 03F0h – 03F1h
SINT32 W (kW × 10
3
) Read
only
PF (output power factor)
122 03F4h
SINT16 1 × 10
3
Read
only
Stator Freq (actual)
125 0400h
SINT16 Hz
10
1
Read only
Control Freq (setpoint)
195 0518h
SINT16 Hz
10
1
Read only
Rotor Speed (actual)
22 0264h
SINT16 rpm
Read only
Control Speed (setpoint)
21 0260h
SINT16 rpm
Read only
Operating Time
39 02A8h – 02A9h
UINT32 h × 10
2
(one tick per every 36 s)
Read only
Running Time
40 02ACh – 02ADh
UINT32 h × 10
2
(one tick per every 36 s)
Read only
Serial Control Parameters
MODE 34
0294h
UINT16
1 = Manual
2 = Auto
3 = Bus
SMODE (Command)
35 0298h
UINT16
0 = Stop
081h = Run (from terminal)
101h = Run (from Input setpoint)
Input Freq Setpoint
124 03FCh
SINT16 Hz
10
1
Input Speed Setpoint
20 025Ch
SINT16 rpm
Inverter Status with Ack
38 02A4h
UINT16 Status code, see description
Read only
Inverter Status w/out Ack
38 02A5h
UINT16 Status code, see description
Read only
Alternative Serial Control
Drive Control
18 0254h
UINT16 Bit field, see description
Drive Status
19 0258h
UINT16 Bit field, see description
Read only
6.1.1 Read status and actual values
If the inverter is controlled from terminals (e.g. run signal, analog input etc.), you can still use the Modbus interface
for continuously reading status and actual values. First part of table above contains a selection of readable
parameters that could be of interest. For status information, either read the Inverter status which returns a status
code, or read the Drive status which reports status using a bit field (both described in following sections).
6.1.2 Control inverter using MODE/SMODE/InverterStatus
To control the inverter (Start/Stop, etc) from a bus interface, the run signal (terminal DIN1) must be active. A
common installation would be to strap the run signal to +24V and set parameter Autostart = Off (which is default).
Then the inverter will not start by itself when powered on, but it allows control from bus.
First the master shall set the parameter MODE = 3 (bus) to gain control over the inverter. Then it can use SMODE
to send a start or stop command, see table in previous paragraph. When run command is 081h the inverter will use
3006469-2022-04
