User manual

Installation
4
2.3 User Connections for OpenComms NIC-485
Since the OpenComms NIC-485 can use simultaneous connections two
user connections may be required:
• Modbus 485 connection
• Temporary serial connection for configuration/setup
2.3.1 BMS Port
The Modbus 485 connection will use the terminals marked “Repeater.”
(TB2) The Modbus server uses RTU protocol and will allow for a maxi-
mum of 32 units on 4000ft. of wire on a common line. EIA-485 repeat-
ers may be necessary to accommodate additional units or longer
cables. Point availability may be referenced in the document,
“SiteScan Reference Library,” which may be downloaded at
www.liebert.com
under the OpenComms product family.
2.3.2 Configuration Port / Service Terminal
A temporary serial connection to the interface card is necessary for
configuration and setup.
Using a DB9F-DB9F null-modem cable, connect the “DTE Serial Port”
P18 to an ASCII terminal or computer running terminal emulation
application. HyperTerminal® and Procomm® are examples of termi-
nal emulation applications running on Microsoft Windows® operating
systems. All trademarks are the property of their respective owners.