Siemens S7-300 - D.11 Fast Access to Module Data

Programming without SFB 52 and SFB 53
D.11 Fast access to module data
FM 352 electronic cam controller
216 Operating Instructions, 05/2011, A5E01071724-03
Writing control signals via direct access
The byte addresses are specified relative to the input address of the module. The bit names
correspond to the names in the channel DB.
In STL, you access the data using the PQB (write 1 byte) and PQW (write 2 bytes)
commands.
Address Bit number
7 6 5 4 3 2 1 0
Byte 0 Internal
Byte 1 0 CNTC1_EN CNTC0_EN CAM_EN DIR_P DIR_M 0 0
Byte 2
Byte 3
TRACK_EN
Example: Actual position value (ACT_POS)
The start address of the module is 512
STL
L PID 516 Read the current actual position value
(ACT_POS) with direct access:
Module start address + 4