Connection to a fieldbus
6.3 Communication via PROFIBUS
Inverter with CU240B-2 and CU240E-2 Control Units
Operating Instructions, 07/2010, FW 4.3.2, A5E02299792B AA
125
Figure 6-7
Status evaluation of the inverter via PROFIBUS
Information about the S7 program
The hexadecimal numeric value 047E is written to control word 1. The bits of control word 1
are listed in the following table.
Table 6- 18 Assignment of the control bits in the inverter to the SIMATIC flags and inputs
HEX BIN Bit in
STW1
Significance
Bit in
MW1
Bit in
MB1
Bit in
MB2
Inputs
0
0
ON/OFF1
8
0
E0.0
1
1
ON/OFF2
9
1
1
2
ON/OFF3
10
2
E
1
3
Operation enable
11
3
1
4
Ramp-function generator enable
12
4
1
5
Start ramp-function generator
13
5
1
6
Setpoint enable
14
6
7
0
7
Acknowledge fault
15
7
E0.6
0
8
Jog 1
0
0
0
9
Jog 2
1
1
1
10
PLC control
2
2
4
0
11
Setpoint inversion
3
3
0
12
Irrelevant
4
4
0
13
Motorized potentiometer ↑
5
5
0
14
Motorized potentiometer ↓
6
6
0
0
15
Data set changeover
7
7
In this example, inputs E0.0 and E0.6 are linked to the -bit ON/OFF1 or to the "acknowledge
fault" bit of STW 1.
The hexadecimal numeric value 2500 specifies the setpoint frequency of the inverter. The
maximum frequency is the hexadecimal value 4000 (also see Data exchange via the fieldbus
(Page 103)).
The control cyclically writes the process data to logical address 256 of the inverter. The
inverter also writes its process data to logical address 256. You define the address area in
HW Config, seeInserting the inverter into the STEP 7 project (Page 109).