Emerson Vilter MicroVission - Remote Control Via Direct I;O (Hard-Wired

C - 6
MicroVission Controller • Operation and Service Manual • Emerson • 35391MV 1.3
Appendix C • Remote Control and Monitoring
Remote Control via Direct I/O (Hard-wired)
Remote Control of the compressor can also be ac-
complished using hard-wired inputs. These include
Remote Start-Stop digital input, Remote Increase digi-
tal input and Remote Decrease digital input. For com-
munication register information, refer to Appendix B:
Communication Table.
Conguration Screen Setup
RefertoFigureC-1.CongurationScreen(Page3).
For Direct I/O control:
• Congurethe“ActiveRemoteControl”drop-down
box to “Direct I/O”. This selection activates the
Remote Start-Stop digital input. This is the ONLY se-
lection that activates the Remote Start-Stop digital
input.
• Below the “Active Remote Control” selection box,
check the “Direct I/O” box.
Now radio-buttons for selecting the desired control
method are available:
• Auto Control
• (Digital) Manual Control – Compressor Capacity con-
trolled via Remote Increase and Remote Decrease
Digital Inputs.
• Cap Hold Control – Compressor Capacity controlled
via Remote Capacity % Analog Input.
Auto Control
The compressor is started and stopped based on the sta-
tus of Remote Start/Stop Digital Input, but the compres-
sor capacity is controlled from the internal compressor
control setpoints entered in the MicroVission. The Auto-
cycle setpoints can be enabled or disabled as desired.
(Digital) Manual Control
The compressor is started and stopped based on the sta-
tus of Remote Start/Stop Digital Input, but the compres-
sor capacity is controlled from the Remote Increase and
Remote Decrease Digital Inputs.
Cap Hold Control
The compressor is started and stopped based on the sta-
tus of Remote Start/Stop Digital Input, but the compres-
sor capacity is controlled from an Auxiliary Analog Input.
The Auxiliary Analog Input value will be proportional to
0% - 100% capacity hold value. Auxiliary Analog Input
rangecanbeconguredusingI/Ojumperselectionset-
tings in Instrument Calibration Screen, refer Figure C-8.
For instance, 4mA = 0%, 12mA = 50%, and 20mA = 100%.
Cap Hold Operation without VFD
The Remote Capacity % (Aux Analog Input value) de-
nesthecapacityforthecompressortooperateat.The
MicroVission will load the steps based on the Remote
Capacity % value provided in the range of 0% - 100%.
Forexample,IfthenumberofUnloadersconguredin
conguration screenis4(25%,50%,75%,100%),then
Load Steps would be 0%, 25%, 50% & 75%. Progress bar
on Main Screen should display capacity at which the
compressor is currently operating. The rules of capacity
hold algorithm are:
1. If Remote Capacity % value is greater than or equal to
(NextLoadStep%-Offset),stepwillbeadded.When
Remote Capacity % value is above 20% (25 – 5), then
compressor will operate at 25% capacity and prog-
ress bar should be loaded at 25%, refer Figure C-6.
WhenRemoteCapacity%valueisabove45%(50–5),
then compressor would operate at 50% capacity and
progressbarshouldbeloadedat50%.WhenRemote
Capacity % value is above 70% (75 – 5), then compres-
sor would operate at 75% capacity and progress bar
shouldbeloadedat75%.WhenRemoteCapacity%
value is above 95% (100 – 5), then compressor would
operate at 100% capacity and progress bar should be
loaded at 100%.
2. If Remote Capacity % value is less than or equal to
(Previous Load Step % + Offset), step will be removed.
WhenRemoteCapacity%value isbelow 80%(75+
5), then compressor will operate at 75% capacity and
progressbarshouldbeloadedat75%.WhenRemote
Capacity % value is below 55% (50 + 5), then com-
pressor will operate at 50% capacity and progress bar
shouldbeloadedat50%.WhenRemoteCapacity%
value is below 30% (25 + 5), compressor would oper-
ate at 25% capacity and progress bar should be load-
edat25%.WhenRemoteCapacity%valueisbelow
5% (0 + 5), then compressor would operate at 0% ca-
pacity and progress bar should be loaded at 0%.
3. If Remote Capacity % value varies within the range
of (Previous Load Step % + Offset) and (Next Load
Step % - Offset), then compressor capacity would not
varyandwouldstay at current step. When Remote
Capacity % value is greater than 30% (25 + 5) and
lesser than 45% (50 - 5), then compressor will operate
at 50% capacity and progress bar should be loaded at
50%.
NOTE
Offset is used at Load Step % and is 5%.
NOTE
Once Compressor is Loading or Unloading a step,
next step would be allowed to Load or Unload
respectively only after 5 seconds.