Siemens SIMATIC ET 200pro - STEP 7 Program Example for Cyclic Communication

Appendix
A.2 STEP 7 program examples
SIMATIC ET 200pro FC-2 converter
Operating Instructions, 04/2015, FW V4.7.3, A5E34257324B AB
231
A.2.2
STEP 7 program example for cyclic communication
The controller and inverter communicate via
standard telegram
1. The control specifies con-
trol
word
1 (STW1) and the speed setpoint, while
the inverter responds with status word
1 (ZSW1)
and its actual speed.
In this example, inputs E0.0 and E0.6 are linked
to the ON/OFF1 bit or to the "acknowledge fault"
bit of STW
1.
Control word
1 contains the numerical value
047E
hex. The bits of control word 1 are listed in
the following table.
The hexadecimal numeric value 2500 specifies
the setpoint frequency of the inverter. The max
i-
mum frequency is the hexadecimal value 4000.
The controller cyclically writes
the process data
to logical address
256 of the inverter. The invert-
er also writes its process data to logical a
d-
dress
256. You define the address area in HW
Config.
Table A- 2 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
E
0
0
ON/OFF1
8
0
E0.0
1
1
OFF2
9
1
1
2
OFF3
10
2
1
3
Operation enable
11
3
7
1
4
Ramp-function generator enable
12
4
1
5
Start ramp-function generator
13
5
1
6
Setpoint enable
14
6
0
7
Acknowledge fault
15
7
E0.6