Vaisala HMW90 - Manual (Page 109)

Appendix B _________________________________________________________ Modbus Reference
VAISALA _______________________________________________________________________ 107
Device Identification Objects
HMW90 Modbus conforms to the extended identification level defined in
the Modbus Application Protocol Specification V1.1b. Both stream
access and individual access to the objects is supported.
Basic device identification consists of objects 0x00…0x02. Those values
should be used if the device must be identified to establish its Modbus
capabilities.
Table 45 HMW90 Modbus Device Identification
Object Id Object Name Description
0x00 VendorName “Vaisala”
0x01 ProductCode HMW95
0x02 MajorMinorVersion Software version
(for example, “1.0.0”)
0x03 VendorUrl “http://www.vaisala.com/”
0x04 ProductName HMW90
0x80 SerialNumber Serial number (e.g.
“H0710040”)
0x81 CalibrationDate Date of the last calibration
(for example, “2012-08-07”,
empty if not available)
0x82 CalibrationText Information text of the last
calibration (empty if not
available)
Exception Responses
Table 46 HMW90 Modbus Exception Responses
Code Name Reason
01 ILLEGAL FUNCTION Unsupported function code
02 ILLEGAL DATA ADDRESS Address out of valid ranges
03 ILLEGAL DATA VALUE Otherwise invalid request
Accessing unavailable (unsupported or temporarily missing)
measurement data does not generate an exception. “Unavailable” value (a
quiet NaN for floating point data or 0x0000 for integer data) is returned
instead. An exception is generated only for any access outside the
register blocks defined in Table 40 on page 104.