CHAPTER 11 - PXG200E SYSTEM INTEGRATION143EATON PXG200E User Manual • IM02603001E Rev 5, 11-May-2012 • Firmware Version 5.03:3835Addressing the Target Pass-Through Downstream ModbusDeviceEach “downstream” Modbus device is assigned a unique Modbus TCP pass-through unit ID. This unit ID is the Modbus serial device address on theCOM1 network. This unit ID is used as the Modbus TCP unit identifier by theModbus TCP client when pass-through mode is desired.To access data from a “downstream” pass-through device, the Modbus TCPclient generates a request to the IP address of the PXG200E with the unitidentifier set to access the targeted pass-through “downstream” device.Consult the user information of your Modbus TCP client to determine how toaddress the device with a register address and count.NOTICE: Pass-through can be used to access Modbus Devices addedto the PXG200E device list AND Modbus Devices not added to thePXG device list. The PXG internally manages access to the Modbusdevices to ensure message collisions do not occur.Downstream Device Pass-Through Register MapThe register map for pass-through mode is the register map provided by thedevice vendor on Modbus RTU.Supported Function CodesUsing pass-through mode, the Modbus RTU device documentation specifiesthe supported function codes.SNMPThe PXG200E provides limited SNMPv1 and SNMPv3 functionality whichallows network management software (NMS) to obtain supported MIB datadirectly from the gateway.• Support for RFC 1213 - MIB-II (groups: sys, if, ip, udp, tcp, snmp) isprovided. Reference the file RFC1213-MIB.txt• Support for Meter MIB• Support for PCD MIB (Power Chain Device)Proper configuration of the PXG200E and NMS requires that there be acommunity string match before requested MIB data is returned from thePXG200E. See SNMP on page 111 for instructions on SNMP configuration.BACnet/IPBACnet/IP communication provides read-only data from BuildingAutomation Systems (BASs), so that the PXG200E can be easily integrated ina BAS alongside other BACnet/IP-capable devices.
