Impulse 463E - Manual (Page 59)

© Sealevel Systems, Inc. - 56 - SeaI/O User Manual
Extended Modbus Command Set
Sealevel SeaI/O modules support an extended Modbus command set that allows an
application to easily modify the Slave ID (address) and communication parameters.
(0x45) Get Config
The Get Config request is designed to obtain model and configuration information
for SeaI/O modules and can be used as a mechanism to verify that the unit is
operational and responding. A Get Config request must be issued to a SeaI/O module
before attempting to set the address or the communication parameters of the module.
This simplistic security model is designed to protect the module from multiple get/set
operations that could occur when multiple masters query the same module.
This transaction shows that the SeaI/O module queried is a SeaI/O-410E, operating at
a baud rate of 14400, with no parity. To change the parameters for this module, the
Magic Cookie, 0xCA, is required.
Request Response
Field Name (Hex) Field Name (Hex)
Function 45 Function 45
Model (lower byte) 9A
Bridge Unit 01
Baud Rate 05
Parity 00
Magic Cookie CA
NOTE: If the Get Config response returns (00) for the model number, the
module being queried is outside the original SeaI/O 4xx series.
Query the module using the (0x66) Get Extended Module
Information request to retrieve the full two-byte model number.
NOTE:
There are no exception codes possible with this transaction. The
tables in Appendix A illustrate how to decode transaction data.