Modbus: Remote Slaves - GE Multinet 4 Instruction Manual

SYSTEM ADMINISTRATION
4–86
Field Name
Port ID: A unique identifier for the serial port to which the device is
connected.
Device Address: Modbus/TCP unit identifier assigned to the device.
Valid range = 1-247
Protocol Variant: Specify a serial transmission mode. Valid options are:
Default value = RTU
Priority (DiffServ): Each IP packet generated by this device will be assigned a
DiffServ Code Point (DSCP) based on the priority set by the user.
The priorities are:
Response Timer The amount of time to wait for a response from this device
(msec):
before giving up and sending back a Modbus exception
message.
Send Gateway Specify whether or not to send exception codes. Possible values
Exceptions:
are:
Delete: Set the Delete checkbox in a row in the Existing Devices table
and click Apply Settings to delete that local slave.

4.5.3.5 Modbus: Remote Slaves

This screen enables you to configure the forwarding table used to map Modbus slave
device addresses to remote IP addresses.
MULTINET4 MULTI-PORT SERIAL SERVER & MANAGED SWITCH – INSTRUCTION MANUAL
CHAPTER 4: SYSTEM ADMINISTRATION
Table 4–51: Modbus: Local Slaves
Field Value
• RTU – Messages are binary encoded with CRC and begin
with a silent interval of 3.5 character times.
• ASCII – messages are ASCII encoded with LRC and begin
with a ':' character and end with a CRLF sequence.
• Default – Best Effort Service (DSCP 0). This is normal
queuing.
• Expedited – Expedited Forwarding (DSCP 0x2E)
(RFC2598). This will also result in data from this
port having a higher priority on WAN ports.
• Yes – Send Modbus/TCP exception codes when an error
occurs (for example, timeout).
• No – Remain silent when an error occurs.