Impulse 463N - Manual (Page 79)

©Sealevel Systems, Inc.
SL9049 - 11/2010
SeaI/O Manual 79
Limiting Expansion Port Communications Data Rate Selection is not available on older
SeaI/O units (Before Firmware Version 2). In addition, the following modules do not support
it:
 462
 463
 470
There are situations where it is desirable to limit the range of allowable data rates or lock down
the unit to one specific data rate. This can be performed by sending the “WriteMultipleRegisters
(function 0x16)” MODBUS command to the unit. Address 302 (decimal) should contain the low
order byte of the lower data rate the unit will accept. Address 303 will contain the high order
byte. Note that this command does not cause the rotary switch to be ignored. Therefore, the
rotary switch can be used to reset the defaults range and set the data rate back to 9600. If this
is not desirable, then you can either set the data rate limitation and then set the address range
to prevent the rotary switch from resetting to defaults or you can write to locations 300 through
303 in one “WriteMultipleRegisters” command.
To reset the unit to “normal” operation, you can issue the MODBUS “Reset Range Settings”
(function 0x19).
This setting can also be configured through MaxSSD under the “Range Configuration” tab,
shown below.