Programming the Technological Functions
6-5
FM 353 Stepper Drive Positioning Module
6ES7 353-1AH01-8BG0
6.1.2
Structure of a user program
The diagram below provides an overview of the structure of the user program
(AWP).
OB 100 and OB 86 (in distributed configurations)
Call
of
POS_INIT
The CPU goes to STOP when an error occurs during start-up.
Parameter entry
User DB
User program: Set, reset,
scan signals/data
OB 82
S
Call of
POS_DIAG
S
User program: Open Emergency STOP circuit, reset signals
(the FM was reset or a fatal error occurred in the FM; see “Infor-
mation on error evaluation”)
OB 1 (or other cyclic levels)
S
Call of
POS_CTRL
S
Your user program, the one that is to control your system
S
User program: Error evaluation
Note
GET/PUT functions (SFC 72/73) from/to the FM are not guaranteed to work prop-
erly, that is to say, these functions are not supported, since they are not required.
Parameter initialization data can be modified via the “Modify parameters/data” sig-
nal (user DB, DBX39.3).
Information on signal processing:
The FM 353’s cycle (= 2 ms) and the user cycle (OB 1) are asynchronous to one
another. Depending on the instant of signal transfer to the FM 353, the time it
takes to process signals may be = 1 to < 2 x the FM cycle. This must be taken into
account particularly when user cycles are short. If necessary, the processing status
of the FM 353 should be queried before activating a new action.
Please note that signal/data transmission takes longer/several user cycles in dis-
tributed configurations (see Section 6.9).
Summary of Contents for SIMATIC FM 353
Page 22: ...Product Overview 1 12 FM 353 Stepper Drive Positioning Module 6ES7 353 1AH01 8BG0 ...
Page 32: ...Installing and Removing 3 6 FM 353 Stepper Drive Positioning Module 6ES7 353 1AH01 8BG0 ...
Page 282: ...Description of Functions 9 82 FM 353 Stepper Drive Positioning Module 6ES7 353 1AH01 8BG0 ...
Page 354: ...User Data Block AW DB B 16 FM 353 Stepper Drive Positioning Module 6ES7 353 1AH01 8BG0 ...
