Specifications

v1.05
6.26.09
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Appendix A: CDL Gateway™-Modbus Version
Modbus Version Overview
The Standard Modbus Version offers three host ports in slave mode. They are:
• Modbus RTU Slave over RS-232 via the RJ-11 jack
• Modbus RTU Slave over RS-485 (2-wire or 4-wire) via RJ-45 jack
• Modbus TCP/IP Slave over Ethernet via RJ-45 jack
Other Modbus versions are available upon request such as a Modbus Master version. One
such scenario would be if you had several Modbus RTU Slave devices in the field and want
to aggregate them into a single Modbus Data Map. In this case, we can setup the RS-485 to
be a Modbus Master to poll the slave devices and map all the registers to the RS-232 or
Ethernet port which would be setup as a Modbus Slave. The CDL Gateway™ can also mix
Modbus with other protocols such as BACnet and data maps for most of the popular PLC
manufacturers. One popular scenario is to use the CDL Gateway™ as a Modbus master to
poll several slave devices on RS-485, bring in the engine data, and combine all parameters
into a single data map that is compatible with an Allen Bradley, GE Fanuc, or Siemens PLC.
Contact the factory to discuss your specific application.
Modbus Address Description
The CDL Gateway™-Modbus Version has a very simple, pre-assigned, address system that
starts at 30001 and goes through 30429 for Modbus Function code “4” and 40001-40429 for
Modbus Function Code “3”. Currently, it is necessary to specify whether you will be
using Function Code “3” or “4”. Since this is primarily a monitoring device, our default
version uses Input Registers only The Modbus Data Map is available on the Downloads
page of the Monico, Inc. web site (www.monicoinc.com)
. The data map provides extensive
details needed for successful installation and operation of the Gateway. MAKE SURE YOU
HAVE THIS MANUAL AND THE MODBUS DATA MAP WHEN GOING INTO
THE FIELD TO INSTALL THE GATEWAY.
The same groups of addresses are assigned to all of the Host Ports. Therefore, you can poll
the same registers from either the RS-485 RJ-45 port, the RS-232 RJ-11 Port, or the Ethernet
RJ-45 port. IT IS HIGHLY RECOMMENDED TO DISABLE ANY UNUSED PORTS TO
OPTIMIZE GATEWAY PERFORMANCE.
There are other versions of this device that will simulate the same addresses as our Monico
CCM Translator, but that version needs to be specifically requested. We also offer versions
that utilize other protocols such as BACnet instead of Modbus. Other versions act as remote
devices for Allen Bradley Ethernet IP or GE Fanuc PLC’s, etc. If you are being forced to
convert Modbus into another format or protocol, please give Monico Technical Support a
call. We may be able to save you time and money.