The Momentary Start / Stop (SS) object in a MNB-1000 controller is not working. No output pulses are not being generated.

Issue

The Momentary Start / Stop (SS) object in a MNB-1000 controller is not working.  The OutStrt and OutStp outputs never pulse on as programmed.  The OnPulse and OffPulse times are set to 1 second each.

Product Line

TAC I/A Series

Environment

MNB-1000 with firmware 1.501 or newer

Cause

The On and Off times for a Momentary Start/Stop object fails with a start time or stop time below 2 seconds. The Plant and Remote I/O Module can't do accurate timing below 2 seconds or so by design.

Resolution

Release 1.501 firmware for the MNB-1000 controller allows the Momentary Start / Stop (SS) object to be used with OnPulse and OffPulse intervals of 2 seconds or greater.  This is described in the Release Notes for WPT 5.7 / MNB-1000 1.501 Firmware (F-27526).


    On and Off Pulse timing wrong for Momentary Start/Stop.
    PRN 4677

    Issue:

    The Momentary Start/Stop times in the MNB-1000 are not accurate
    when set for small second increments (1 to 12 seconds)

    Resolution:

    This has been partially fixed in the MNB-1000 firmware.
    Small increments greater than 2 seconds are now accurate.
    See the note on PRN 5011 describing limitations on increments
   
less than 2 seconds.


    On and Off Pulse timing wrong for Momentary Start/Stop.
   
PRN 5011

    Issue:

    The On and Off times for a Momentary Start/Stop object fails with
   
a start time or stop time below 2 seconds. The Plant and Remote IO
    Module can't do accurate timing below 2 seconds or so by design.
    The object still works, but the timing is inaccurate.

    Resolution:

    A note has been added to document F-27356 (revision 3) "WorkPlace
    Tech Tool 5.7 Engineering Guide Supplement" to warn of the
    limitations of this object in the MNB-1000.