User manual
48 www.cooperbussmann.com/wirelessresources
Cooper Bussmann 245U-E Wireless Ethernet Modem & Device Server User Manual
Rev Version 2.19
The layout of the 245U-E I/O registers is summarized in the table below. Each register is internally saved as a 16-bit
unsigned integer value. A Modbus transaction may access the entire 16-bit value of any register. Alternatively,
the most significant bit of a register may be accessed as a discrete value. The main use for the general purpose
I/O registers is for intermediate storage, as when transferring I/O from one Modbus slave device to another. Also
provided is the status of the onboard digital I/O, as well as the status of the wireless link. The 16-bit status register
contains the value FFFF (hexadecimal) for On and 0000 (hexadecimal) for Off. Inverted status registers are also
provided where the registers contain 0000 (hexadecimal) for On and FFFF (hexadecimal) for Off.
Registers Purpose
1–4299 General purpose I/O registers (read/write).
4300 On-board digital input value (read only).
4301 Link status (read only).
4302 Serial gateway connection status (RS232).
4303 Serial gateway connection status (RS485).
4304 TCP-RTU connection status (RS232).
4305 TCP-RTU connection status (RS485).
4306 TCP-RTU Modbus server connection status.
4307 Multicast pipe connection status.
4310 TCP-RTU number of connections (RS232).
4311 TCP-RTU number of connections (RS485).
4312 TCP-RTU number of connections (Modbus server).
4320 On-board digital output value (read/write).
4370 On-board digital input inverted value (read only).
4371 Link status (read only) inverted.
4372 Serial gateway connection status (RS232) inverted.
4373 Serial gateway connection status (RS485) inverted.
4374 TCP-RTU connection status (RS232) inverted.
4375 TCP-RTU connection status (RS485) inverted.
4376 TCP-RTU Modbus server connection status inverted.
4377 Multicast pipe connection status inverted.
4378–4999 Reserved for future use.
Modbus TCP client (master) enables the 245U-E to connect to one or more Modbus TCP servers (slaves). All
Modbus master messages are directed to/from the onboard I/O registers depending on configuration (described
below). The Modbus TCP client may also poll Modbus RTU (serial) devices connected to either the local serial port
or a remote 245U-E serial port by enabling the Modbus TCP to RTU gateway at the corresponding serial port (see
“3.11 Serial Port Configuration”).
Modbus TCP client functionality allows a maximum of 100 mappings to be configured and a maximum of
25different Modbus TCP servers. Modbus TCP server (slave) enables the 245U-E to accept connections from one
or more Modbus TCP clients (masters).