PROJECT
INCORPORATING COLD CHAIN
The banana ripening rooms were installed at the Springs Fresh Produce Market.
PLC HMI screen for controlling of ripening parameters. The pump control uses custom software
with Free Advance and Schneider Electric
VSDs to regulate the chilled water supply
pressure. Rotating the pumps maintains
equal running hours and should a fault
occur on one set, the control logic
disables the pump, produces an alarm
and initiates the standby pump until the
fault is resolved.
All values, settings and commands are
accessible through the remote Human
Machine Interface (HMI) of the PLC or
through the TelevisGO monitoring system
graphic layout. The alarm management
is crucial and categorised for critical and
non-critical instances, as there is a fine line
between annoying the client and making
sure they know when to react and how
severe a potential problem is.
Fresh air intact / extract system. Bananas in the old ripening rooms.
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www.coldlinkafrica.co.za
“Using Teamviewer, we have access
to a complete overview of the site and
depending on the user’s permissions the
client/contractor can ascertain and dig
down to the fault from anywhere and any
device,” explains Milne. “However, if the
fault cannot be resolved or understood —
on an integrator level, from the monitoring
system — we are able to fault find the
encrypted source code of the controller
directly through the Ethernet port of each
PLC.”
As a standard, Free Advance comes
with built-in Ethernet, and because the
developing tool (Free Studio PLUS) is free,
they are able to remotely install it onto the
TelevisGO, or any PC on the network and
connect to the PLC to view and if need
be, edit and load source code.
COLD LINK AFRICA • June 2019