CHAPTER 3: OPERATION 12-5-97 PAGE 24
2 - Use_Term_Values
When communications are lost, the drive will receive the control commands from the terminal (as if option
card was placed in manual mode). When network communications are restored, the drive will immediately
follow the commands of the last Poll messages (lockout state is not activated).
WARNING: When in this mode, the drive will revert to the current state set at the
terminal. It is the user’s responsibility to preset this to a safe state.
The user can take local (terminal) control of the drive while in this mode by switching to manual. However,
if the mode is switched back to automatic while the network is inactive, the drive will continue to use the
terminal controls until the network is made active.
NOTE: If FWD or REV contacts are closed at terminal at powerup an ER6 will be
generated.
3.7 Lockout State
3.7.1
The option card will enter lockout state on power up or when receiving a Poll command with
zero data length or under certain losses of communications. Should the option card be in lockout state
while in automatic mode with the network active, the option card will ignore further Poll commands
requesting forward or reverse motion and hold the drive at ‘STOP’. Lockout state is indicated by bit 0 in
the second byte of the Drive status Poll response. Refer to ‘Loss-of-Network actions’ described above to
determine when lockout state is activated during loss of communications.
3.7.2
Lockout state is reset by simply sending a Poll command where both the Fwd and Rev bits of
byte 0 in the Drive Control Poll request are reset. Maintaining the drive at ‘STOP’ until the proper
sequence of control bits is received prevents inadvertent startup when PLCs are switched from HALT to
RUN after maintenance halts or network fault conditions.
