Basler Electric BE1-11 Modbus Protocol - Manual (Page 13)

9424200774 Rev B 7
While in the listen only mode, the BE1-11 continues to monitor all queries. The BE1-11 does not respond
to any other query until the listen only mode is removed. All write requests with a query to Preset Multiple
Registers (Function Code = 16) are also ignored. When the BE1-11 receives the restart communications
query, the listen only mode is removed.
Device Address
Function Code =
08 (hex)
Subfunction Hi = 00 (hex)
Subfunction Lo = 04 (hex)
Data Hi = xx (don't care)
Data Lo = xx (don't care)
CRC Hi error check
CRC Lo error check
Preset Multiple Registers
A preset multiple registers query could address multiple registers in one slave or multiple slaves. If the
query is a broadcast (device address = 0), no response message is returned.
Query
A Preset Multiple Register query message requests a register or block of registers to be written. The data
block contains the starting address and the quantity of registers to be written, followed by the Data Block
byte count and data. The BE1-11 will perform the write when the device address in query is a broadcast
address or the same as the BE1-11 Modbus Unit ID (device address).
A register address of N will write Holding Register N+1.
Data will cease to be written if any of the following exceptions occur.
•
Queries to write to Read Only registers result in an error response with Exception Code of “Illegal
Data Address”.
•
Queries attempting to write more than 100 registers cause an error response with Exception
Code “Illegal Function”.
•
An incorrect Byte Count will result in an error response with Exception Code of “Illegal Data
Value”.
•
There are several instances of registers that are grouped together to collectively represent a
single numerical BE1-11 data value (i.e. - floating point data, 32-bit integer data, and strings). A
query to write a subset of such a register group will result in an error response with Exception
Code “Illegal Data Address”.
•
A query to write a not allowed value (out of range) to a register results in an error response with
Exception Code of “Illegal Data Value”.
Device Address
Function Code =
10 (hex)
Starting Address Hi
Starting Address Lo
No. of Registers Hi
No. of Registers Lo
Byte Count
Data Hi
Data Lo
.
.
Data Hi
Data Lo
CRC Hi error check
CRC Lo error check
BE1-11 General Information