Siemens SIMATIC S7-300 Manual page 224

Description of Functions
9.3.7 Request application data (job no. 18)
Overview
A selection of up to four display data items whose values can be read out
with "read application data" (see Section 9.3.13).
Code table:
The code should be entered in CODE_AP1...AP4.
These values are always updated in the module cycle.
The selection is stored on the FM, i.e. you only need to make the selection
once and read the correponding values cyclically (job no. 105).
9-48
Code
0 No parameter request
1 Actual position
2 Actual velocity
3 Distance to go
4 Setpoint
5 Total current coordinate shift
6 Speed
16 DAC output value
17 Actual encoder value
18 Pulse errors
19 K factor
v
20 Following error
21 Following error limit
22 s Overshoot/Switch readjustment in Reference Point Approach mode
23 Approach time Te (ms)/drive constant Ta (ms) in Control mode
Significance
FM 354 Servo Drive Positioning Module