Emerson Vission 20/20 Operation And Service Manual page 199

Appendix B • Vission 20/20 Application Procedures
registers within the Modbus range of 40500 through
40513 can occur. If Remote Lock is ON, then writes
within this region cannot occur. These registers
are the compressor control registers (Start, Stop,
Caphold etc). Remote Lock is typically used to lock
out a PLC or central computer while the operator is
operating the compressor locally. The Remote Lock
button is located directly below the Compressor
STOP button. The status of Remote Lock is shown in
the upper left corner of the Main Screen.
RESTART ON POWER FAILURE
• The Vission 20/20 allows for selection of different
operations to occur after a power failure has oc-
curred. The selections determine what mode of
operation the 20/20 will be placed after the power is
restored to the panel. This should decided upon and
setup prior to communicating to the 20/20 panel.
1. Always
2. Never
3. Timed
4. Remote Lock Off
5. Boot in Remote (Direct I/O)
1. Always
• If compressor was off prior to power failure, it will
stay off after power is restored.
• If compressor was running prior to power failure,
it will begin an Auto-restart sequence as soon as
power is restored.
• In both cases, the Remote Lock will be ON after
power is restored, which means it will not accept any
"writes" via communication, within the Compressor
Command register region, until someone walks up
to the panel and presses Unit Start-> Remote.
2. Never
• The compressor will not restart after power is
restored. The Remote Lock will be ON after power
is restored, which means it will not accept any
"writes" via communication, within the Compressor
Command register region, until someone walks up
to the panel and presses Unit Start-> Remote.
3. Timed
• The compressor WILL attempt a restart after power
is restored and the Max Restart After Power Failure
timer has timed out. The Remote Lock will be ON
after power is restored, which means it will not
accept any "writes" via communication, within
the Compressor Command register region, until
Vission 20/20 • Operation and Service Manual •Vilter/Emerson • 35391SC 2.0
someone walks up to the panel and presses Unit
Start-> Remote.
4. Remote Lock Off
• The Vission 20/20 panel will boot up with the
Remote Lock OFF which will allow the panel to
accept all remote control commands, via commu-
nication, immediately after power is restored to the
panel.
5. Boot in Remote (Direct I/O)
• The Vission 20/20 panel will boot up with the
Remote Lock OFF and be placed into REMOTE mode,
which will allow the panel to accept Direct I/O com-
mands immediately after power is restored to the
panel.
COMMON REGISTER SETUP FOR CONTROLLING
THE VISSION 20/20 (COMPRESSOR CONTROL)
VIA COMMUNICAITONS
Register Setup and Control Scenario
• The Vission 20/20 panel fi rst needs to be placed in
REMOTE mode before Compressor Control com-
mands (Registers 40500 through 40513) can be
sent. To do this, press the green UNIT START but-
ton, then REMOTE.
Modbus Register 40501 - Active Remote Control
Reading this register can be used to verify the Active
Remote Control mode, which was previously setup from
the Confi guration screen. Writing to this register can
change the Active Remote Control mode, however this
is not common.
• 0 = None (internal local setpoints will used to control
the compressor).
• 1 = Direct I/O (hardwired control - via digital inputs.
Refer to wiring diagram.)
• 2 = Serial (serial communications via RS485 Modbus
RTU ).
• 3 = Ethernet (Modbus TCP or Ethernet IP
communications.)
Typically, the following registers are setup (written to)
before a "Start" command is issued to the compressor:
B - 43