Modbus Read, Write and Override Parameters plus Exception Codes
3/07 UDC3500 Universal Digital Controller Product Manual 349
value into EEROM by pressing some key other than the Increment or Decrement
keys, then there is an additional 15 second timeout delay after which time the
changed value is automatically saved into EEROM. During this 15 second period, the
controller will continue to respond with a BUSY exception message to any
MODBUS WRITE communications transaction, as the controller is waiting for the
operator to finish making changes to the setpoint via the keyboard. To minimize this
busy period, the operator should always end a setpoint change by pressing any key
other than the Increment or Decrement keys. This will reduce the time that the
controller sends back busy exception messages to the host computer. MODBUS
READ communication transactions are not affected, the controller will respond with
a normal message to any READ command during the 15 second period.
To Next Page
Loading...
