User`s guide

Appendix A _________________________________________________________ Modbus Reference
VAISALA _______________________________________________________________________ 177
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 42 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 43 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 36 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 172.