Checkback Signals - Siemens SIMATIC S7-300 Manual

Description of Functions
9.1.2

Checkback signals

Overview
The checkback signals indicate the processing status of the axis and report it
to the user program.
Table 9-2 describes the checkback signals and their functions.
Table 9-2 Checkback signals
Symbol
Significance S gn f cance
English German
TST_STAT TFGS Sw./over P bus
interface com-
plete
OT_ERR BF/FS Operator/travel
error
DATA_ERR DF Data error
PARA PARA Parameterize
START_EN SFG Start enable
9-6
Function Funct on
Communication with the user program is not possible, since the P bus
interface has been switched over for operation with the start–up tool.
... signaled to the user if an operator-control error or travel error is
pending (e.g. unallowed control signal has been set, (R+) and (R–) set
simultaneously) An error message causes the movement to be canceled.
see Chapter 11
... is reported to the user when a data error occurs.
see Chapter 11
... module parameterized. All machine data applicable for control of an
axis are present on the module.
... signals that the FM 354 is ready for positioning and output.
"Start enable" is set:
– if no static stop or error is pending and the drive enable is pend-
ing
– if the mode setting and mode checkback match (after mode
change)
– if no axis functions (including M output, dwell time) are active,
or after functions have been completed
– for further processing of a function interrupted with unpro-
grammed stop
– in Automatic mode, after M0, M2, M30 or at end of block in
Automatic single-block mode
"Start enable" is deleted:
– if a function has been started and is active, or
– if a start condition is active (stat.)
– if there is an error and an unprogrammed stop
– in follow–up mode
Without Enable Start, none of the functions that can be operated
with Travel Plus, Travel Minus and Start can be executed.
FM 354 Servo Drive Positioning Module