© 2014 Pentair Equipment Protection
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ALARM INPUT CONNECTION
The Remote Access Control can accept a dry contact/switch input via the two 18 AWG white wires located at the
back of the air conditioner. This input is associated with the controller display alarm mnemonic TP (door open
and/or smoke detected). [To use this feature, remove the splice connector connecting the two white wires and
connect customer supplied enclosure door switch in its place.]
ALARM CONDITION DISPLAY
There are seven possible non-latching alarm conditions detectable by the controller and are indicated on the
controller display. All alarms can also be accessed through the Ethernet and USB connections.
Alarm Mnemonic
Description
Cause
Result
Alarm Relay
TP
General Alarm
Door open and/or smoke
detected
Unit turns off for duration
of alarm
Relay Contacts Close
LA
High Pressure Warning
MALF high pressure
switch opens
No effect on function
N/A
E1
Air Inlet Temperature
Sensor Alarm
Sensor Failure
Unit turns off for duration
of alarm
Relay Contacts Close
E2
Air Outlet Temperature
Sensor Alarm
Sensor Failure
Unit turns off for duration
of alarm
Relay Contacts Close
Ht
High Temperature Alarm
Default = 125 F
Cabinet over temperature
Alarm clears at default
setting -2 F
No effect on function
Relay Contacts Close
Lt
Low Temperature Alarm
Default = 40 F
Cabinet under
temperature
Alarm clears at default
s27 F
No effect on function
Relay Contacts Close
A1
Frost Alarm
Evaporator coil frozen
Alarm clears at 59 F
Compressor and
Evaporator fan off for
duration of alarm
Relay Contacts Close
AIR CONDITIONER UNIT COMMUNICATION FEATURES
Air conditioner units equipped with communication capabilities provide SNMP, EtherNet/IP and Modbus TCP
protocols through Ethernet and Modbus RTU protocol via USB. Hoffman
®
Cooling has a PC Interface Tool
available for download that can utilize either mode to communicate with the air conditioner unit.
USB COMMUNICATION
This communication mode allows direct connection of a PC to the air conditioner unit. The protocol
supported is Modbus RTU. Use the PC Interface Tool to communicate with the air conditioner unit. A
MINI-b USB connection is provided.
ETHERNET COMMUNICATION
This communication mode allows remote connection to the air conditioner unit using SNMP, EtherNet/IP
and Modbus TCP protocols. Customers using their own software can download a MIB file for SNMP, EDS
file or EtherNet_IP Object file for EtherNet/IP and Coil_Register file for Modbus TCP.
Note: ACU has a default IP Address of 192.168.1.2
Both Ethernet and USB communication modes allow the ability to:
• Read ACU inlet and outlet air temperatures
• Read and change Cooling Set-point and Cooling Differential
• Read and change Heating Set-point, Heating Differential
• Read and change High and Low Temperature Alarm Settings
• Read and change Gateway IP Address, Device IP Address, Subnet Mask, Trap IP Address and Community
• Read and change Unit Identification
• Read and change the state of IP addressing (static or dynamic)
• Read current Alarm Status
SOFTWARE AND CONFIGURATION FILE DOWNLOADS
The PC Interface Tool, MIB file, EDS file, EtherNet_IP Object file and Coil_Register file can be downloaded
from www.hoffmanonline.com.
