Experimental Physics and
Industrial Control System

Folks,

 

R3-1 of the Modbus module is now available.  This is from the release notes.

 

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- Added support for the asynInt64 interface between device support and the driver.

 

- Added support for 22 new data types including unsigned integers, 64-bit integers, byte-swapped versions of all 32-bit and 64-bit data types, and zero-terminated strings.

  INT32_LE_BS Byte-swapped Int32 little-endian

  INT32_BE_BS Byte-swapped Int32 big-endian

  UINT32_LE Unsigned Int32 little-endian

  UINT32_BE Unsigned Int32 big-endian

  UINT32_LE_BS Byte-swapped unsigned Int32 little-endian

  UINT32_BE_BS Byte-swapped unsigned Int32 big-endian

  INT64_LE Int64 little-endian

  INT64_BE Int64 big-endian

  INT64_LE_BS Byte-swapped Int64 little-endian

  INT64_BE_BS Byte-swapped Int64 big-endian

  UINT64_LE Unsigned Int64 little-endian

  UINT64_BE Unsigned Int64 big-endian

  UINT64_LE_BS Byte-swapped unsigned Int64 little-endian

  UINT64_BE_BS Byte-swapped unsigned Int64 big-endian

  FLOAT32_LE_BS Byte-swapped Float32 little-endian

  FLOAT32_BE_BS Byte-swapped Float32 big-endian

  FLOAT64_LE_BS Byte-swapped Float64 little-endian

  FLOAT64_BE_BS Byte-swapped Float64 big-endian

  ZSTRING_HIGH Zero terminated string data. One character is stored in the high byte of each register.

  ZSTRING_LOW Zero terminated string data. One character is stored in the low byte of each register.

  ZSTRING_HIGH_LOW Zero terminated string data. Two characters are stored in each register, the first in the high byte and the second in the low byte.

  ZSTRING_LOW_HIGH Zero terminated string data. Two characters are stored in each register, the first in the low byte and the second in the high byte.

 

Note: For big-endian formats the _BE format is order in which an IEEE value would be stored on a big-endian machine, and _BE_BS swaps the bytes in each 16-bit word relative to IEEE specification. However, for little-endian formats the _LE format is byte-swapped within each 16-bit word compared how the IEEE value would be be stored on a little-endian machine.

The _LE_BS format is the order in which an IEEE value would be stored on a little-endian machine. This is done for backwards compatibility, because that is how _LE has always been stored in previous versions of this modbus module.

 

- Converted the documentation from HTML to REst, and moved to https://epics-modbus.readthedocs.io/en/latest/.

 

- Converted the release notes from HTML to Github Markdown and moved to https://github.com/epics-modules/modbus/blob/master/RELEASE.md.

 

- Improved debugging by returning the actual number of bytes transfered in read operations in the interpose interface functions.

 

- Fixed writing strings with absolute addressing.

 

- Fixed the length limit of function codes 1,2,5 and 15. It was previously allowing allowing 2015 and 1983 bits, rather than 2000 and 1968.

 

- Added support for specifying the maximum length of strings in the drvUser field. STRING_HIGH=17 would result in a 16 character long string (plus terminating 0 byte)

 

- Handle errors in drvModbusAsynConfigure.

 

Thanks to Krisztian Loki from ESS for the ZSTRING support and the last 4 fixes above.

 

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Home page:

https://github.com/epics-modules/modbus

 

Documentation (new location):

https://epics-modbus.readthedocs.io/en/latest/

 

Release notes (new location):

https://github.com/epics-modules/modbus/blob/master/RELEASE.md

 

Cheers,

Mark