Siemens SIMATIC S7-300 Manual page 197

Table 9-4 Control actions for "Reference point approach" mode (examples), continued
Signal name
Control action 5, ambiguous direction command (special situation)
Control signals:
Direction plus [R+]
Direction minus [R–]
Checkback signals:
Travel minus [FR–]
Processing in progress [BL]
Control signals:
Direction plus [R+]
Direction minus [R–]
Checkback signal:
Start enable [SFG]
Control action 6, cancel servo enable (special situation)
Single function "servo en-
able" (job no. 10)
Checkback signals:
Operator control/travel error
[BF/FS]
Travel minus [FR–]
Processing in progress [BL]
Control signal:
Acknowledge operator con-
trol/travel error [BFQ/FSQ]
Checkback signals:
Start enable [SFG]
FM 354 Servo Drive Positioning Module
Level
[R+] is defined although [R–] is active.
The ambiguous direction command causes the axis to stop.
[FR–] and [BL] are canceled, and an error is output.
The [SFG] does not reappear until [R+] and [R–] have been
canceled].
The "servo enable" is deactivated during the traversing
movement.
The axis is stopped abruptly and outputs an error. [FR–] and
[BL] are canceled.
When the error is acknowledged, the error message is can-
celed and the start enable is activated.
Description of Functions
Explanation
9-21