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Serial Port Profiles
Modbus Slave IP Settings Field Descriptions
This window is used to configure the Modbus Slaves.
Idle Timeout
Use this timer to close a connection because of inactivity. When the
Idle
Timeout
expires, the IOLAN will end the connection.
Range:
0-4294967 seconds (about 49 days)
Default:
0 (zero), which does not timeout, so the connection is permanently
open.
Enable Modbus
Exceptions
When enabled, an exception message is generated and sent to the initiating
Modbus device when any of the following conditions are encountered: there is
an invalid UID, the UID is not configured in the Gateway, there is no free
network connection, there is an invalid message, or the target device is not
answering the connection attempt.
Default:
Enabled
Character Timeout
Used in conjunction with the Modbus RTU protocol, specifies how long to
wait, in milliseconds, after a character to determine the end of frame.
Range:
10-10000
Default:
30 ms
Message Timeout
Time to wait, in milliseconds, for a response message from a Modbus TCP or
serial slave (depending if the Modbus Gateway is a Master Gateway or Slave
Gateway, respectively) before sending a Modbus exception.
Range:
10-10000
Default:
1000 ms
Session Strings
Controls the sending of ASCII strings to serial devices at session start as
follows;
z
Send at Start
—If configured, this string will be sent to the serial device
on power-up of the IOLAN or when a kill line command is issued on this
serial port. If the "monitor DSR" or "monitor DCD" options are set, the
string will also be sent when the monitored signal is raised.
Range:
0-127 alpha-numeric characters
Range:
hex 0-FF
z
Delay after Send
—If configured, will inset a delay after the string is sent
to the device. This delay can be used to provide the serial device with time
to process the string before the session is initiated or terminated.
Default:
10 ms
