Vaisala MMT330 - Manual (Page 169)

Appendix A _________________________________________________________ Modbus Reference
VAISALA _______________________________________________________________________ 169
NOTE Resetting, powering up the transmitter, or reselecting the Modbus mode
(by serial command or with the user interface) resets all Modbus
diagnostic counters and cancels any “Listen Only” mode.
Device Identification Objects
MMT330 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.
Table 41 MMT330 Modbus Device Identification
Object Id Object Name Description
0x00 VendorName “Vaisala”
0x01 ProductCode Product code (e.g. “MMT330”)
0x02 MajorMinorVersion Software version (e.g. “5.10”)
0x03 VendorUrl “http://www.vaisala.com/”
0x04 ProductName Product name of the instrument
0x80 SerialNumber Serial number (e.g. “D0710040”)
0x81 CalibrationDate Date of the last calibration
(e.g. “2011-02-07”, empty if not
available)
0x82 CalibrationText Information text of the last calibration
(empty if not available)
Exception Responses
Exception responses from the transmitter are according to the Modbus
Application Protocol Specification V1.1b.
Table 42 MMT330 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) registers
inside ranges specified in Table 35 does not generate an exception.
“Unavailable” value (a quiet NaN for floating point data or zero for
integer data) is returned instead. An exception is generated only for any
access outside the register blocks defined in section Register Map on
page 164.