Honeywell XYR 400E User Manual page 56

Registers
1 – 4299
4300
4301
4320
4370
4371
4372-4999
Modbus TCP Client (Master) enables the XYR 400E to connect to one or more Modbus TCP
Servers (Slaves). All Modbus Master messages are directed either to/from the onboard I/O registers
depending on configuration (described below). The Modbus TCP Client may also poll Modbus
RTU (i.e. serial) devices connected to either the local serial port or a remote XYR 400E serial port
by enabling the Modbus TCP to RTU gateway at the corresponding serial port (see section "3.13.3
Modbus TCP to RTU Gateway"). Modbus TCP Client functionality allows connections to a
maximum of 25 different Modbus TCP Servers.
Modbus TCP Server (Slave) enables the XYR 400E to accept connections from one or more
Modbus TCP Clients (Masters). All Modbus transactions routed to the onboard Modbus TCP Server
are directed either to/from the onboard general purpose I/O registers. The Modbus TCP Server is
shared with the Modbus TCP to RTU Gateway, so that the Modbus "Device ID" is used to
determine if a Modbus transaction is to be routed to the onboard Modbus TCP Server or to a
Modbus RTU device connected to the serial port. Care should therefore be taken that all serially
connected Modbus devices use a different Modbus Device ID (i.e. Modbus Slave Address) to the
onboard Modbus TCP Server. Up to 32 separate connections to the Modbus TCP Server are
supported.
Modbus RTU (serial) Master functionality is achieved by combining the Modbus TCP Client
(Master) and Modbus TCP to RTU Gateway. Simply specify a Modbus TCP Client (Master)
connection to a Modbus TCP Server where the server is the address of any XYR 400E with Modbus
TCP to RTU Gateway enabled. Care should be taken to ensure that the Device ID (i.e. Modbus
Address) of the serial device is different to the Device ID of the onboard Modbus TCP Server of the
XYR 400E that the serial device is connected to.
The XYR 400E provides a configurable option to automatically reset the value of the onboard I/O
registers to zero in the event of a communications failure. If a valid Modbus transaction directed
to/from a given register has not been completed for longer than a configurable timeout, then the
value of that register will be reset to zero.
Version 1
5/1/08
Purpose
General purpose I/O registers (read/write)
On-board Digital Input value (read only)
Link Status (read only)
On-board Digital Output value (read/write)
On-board Digital Input inverted value (read only)
Link Status inverted (read only)
Reserved for future use
XYR400E Ethernet Modem 56