CSR-20 & CSR-40, September 1999
Electrical Maintenance
Integrated Remote Monitor Unit
5-3
Integrated Remote Monitor Unit (IRMU)
(Option)
An integrated remote monitoring unit box is mounted above
the compressor compartment. The remote monitor unit con-
sists of a printed circuit board that gathers information from
the THERMOGUARD
µ
P-D Controller and transmits it to a
remote computer for operator viewing.
On command from a remote computer, the remote moni-
toring unit collects information from the
µ
P-D Controller via a
serial communications port. Data is then transmitted to the
remote computer over the refrigeration system’s 460/380 Vac,
60/50 Hz, 3-phase electric power lines.
The remote monitoring unit allows extensive unit status
information including container serial number, return air tem-
perature, alarm indications, unit operating mode, recent defrost
(within the last 15 minutes), and unit shutdown due to a fault
to be transmitted to a remote computer for viewing. It also per-
mits the operator to request additional information or take
action to initiate defrost, change the current controller setpoint,
and operate pre-trip inspection or diagnostic routines.
System
Acronym
Description
CCU
Communication Control Unit
DSEL
Deselect
IRMU
Integrated Remote Monitoring Unit
MMU
Master Monitor Unit
RMU
Remote Monitoring Unit
RXD
Receive Data
TXD
Transmit Data
VREC
12 Vdc Nominal Voltage
Diagnosis
In the communications system, the Master Monitor Unit
(MMU) and the Communication Control Unit (CCU) operate
under a close relationship, as shown in the Remote Monitor
Unit Diagram. The MMU checks on the CCU and if no
response is received, sends a CCU communications error mes-
sage to the screen. If this error does occur, attempt to re-boot
or re-start the system at least once. This problem is relatively
Remote Monitor Unit Diagram — Unit Model CSR-40-116
MMU
= Master Monitor Unit
CCU
= Communication Control Unit
RMU
= Remote Monitor Unit
TBU
= Transformer Bypass Unit
