Lenze MCH Series Drives - Manual (Page 14)

11 RG-MHLON
Drive Setup & Programming
56 SERIAL LOSS This parameter sets the action to be taken in the event that the LON has modified
the speed command or started the drive and a serial watchdog timeout occurs. The
options for this parameter are FAULT (default) and PRESET#3.
If FAULT is selected and the drive is running when a serial watchdog timeout occurs
the drive will trip into a SERIAL FAULT stopping the drive and taking it out of serial
control. A fault reset command (issued via LON parameter nviResetFault), a keypad
stop or a terminal stop is required to clear the fault.
If PRESET#3 is selected and a timeout occurs the drive will continue to run at the
speed defined in Drive Parameter #3 (PRESET #3). If the drive is stopped (KSTOP,
RSTOP, SSTOP or FAULT) or a valid speed command is received from the LON, the
drive will return to its normal speed reference.
When Drive Parameter #30 (CONTROL) is set to SERIAL SPEED, the speed reference
MUST be the drive keypad (-KEY or -MKB) for the serial loss action to take effect.
When CONTROL is set to SERIAL AUTO the serial loss action will take effect with any
speed reference.
This parameter also defines the action to be taken in the event that the drive is
placed OFFLINE or a Receive Heartbeat timeout (RX_FAIL) occurs.
57 SERIAL This parameter needs to be set to either WITH TIMER (default) or W/O TIMER for the
drive to communicate through the serial link. Serial communications will not work if
this parameter is set to DISABLED.
60 SERIAL TIMEOUT This parameter makes the serial watchdog timeout period selectable. It has a
minimum value of 10 seconds and maximum value of 255 seconds. The default is
30 seconds. If no action is to be taken when a serial watchdog timeout occurs, Drive
Parameter #57 (Serial) should be set to W/O TIMER. This will disable the watchdog
timer. Otherwise Drive Parameter #57 (Serial) should be set to WITH TIMER. The
action to be taken when a timeout occurs is then determined by Drive Parameter
#56 (Serial Loss).
NOTE: Receive heartbeat timeouts and OFFLINE occurrences are not affected by the
setting of Parameter 60.