Siemens SINAMICS V20

Communicating with the PLC
7.2 MODBUS communication
SINAMICS V20 Converter
190 Operating Instructions, 10/2019, A5E34559884-012
Register No.
Description
Ac-
cess
Unit
Scaling
factor
Range or On/Off
text
Read
Write
Converter
MODBUS
511
40512
Proportional gain
R/W
-
1000
0.000 - 65.000
P2280
P2280
512
40513
Integral gain
R/W
s
1
0 - 60
P2285
P2285
513
40514
Differential gain
R/W
-
1
0 - 60
P2274
P2274
514
40515
PID upper limit
R/W
%
100
-200.0 - 200.0
P2291
P2291
515
40516
PID lower limit
R/W
%
100
-200.0 - 200.0
P2292
P2292
519
40520
PID setpoint output
R
%
100
-100.0 - 100.0
r2250
r2250
520
40521
PID feedback
R
%
100
-100.0 - 100.0
r2266
r2266
521
40522
PID output
R
%
100
-100.0 - 100.0
r2294
r2294
549
40550
Parameter number
RW
-
1
0 - 65535
-
-
550
40551
Parameter index
RW
-
1
0 - 65535
-
-
551
40552
Reserved
RO
-
-
-
-
-
553
40554
Parameter upper word
RW
-
1
0 - 65535
-
-
554
40555
Parameter lower word
RW
-
1
0 - 65535
-
-
557
40558
Parameter upper word
RO
-
1
0 - 65535
-
-
558
40559
Parameter lower word
RO
-
1
0 - 65535
-
-
600
40601
DS47 control
R/W
-
-
-
-
-
601
40602
DS47 header
R/W
-
-
-
-
-
602
40603
DS47 data 1
R/W
-
-
-
-
-
…
…
…
…
721
40722
DS47 data 120
R/W
-
-
-
-
-
Program example
The program below gives an example of calculating the CRC for MODBUS RTU.
unsigned int crc_16 (unsigned char *buffer, unsigned int length)
{
unsigned int i, j, temp_bit, temp_int, crc;
crc = 0xFFFF;
for ( i = 0; i < length; i++ )
{
temp_int = (unsigned char) *buffer++;
crc ^= temp_int;
for ( j = 0; j < 8; j++ )
{
temp_bit = crc & 0x0001;
crc >>= 1;
if ( temp_bit != 0 )
crc ^= 0xA001;
}
}
}