Vaisala PTU300 - Manual (Page 213)

Appendix C _________________________________________________________ Modbus Reference
VAISALA _______________________________________________________________________ 211
Status Registers (Read-Only)
Table 46 Status Registers
Name Address Description
Fault status 0513 1 = No errors
Online status 0514 1 = Online data available
Pressure stability 0515 1 = OK
Error code (bits 15…0) 0516 Bit field that represents the
error codes listed in Table 36
on page 158. Active errors are
set to 1. For example, if bit 14
is set to 1, error code E14 is
active.
Error code (bits 31…16) 0517
Error information can retrieved also with function code 08, sub-function
02.
NOTE Basic status information of the PTU300 transmitter is also available with
the Read Exception Status function code 07. For details, see section
Exception Status Outputs on page 212.
Configuration Registers
Configuration parameter registers are used to configure the measurement.
Writing out-of-range values is silently ignored.
Table 47 Configuration Parameter Registers
Name Float Integer Valid Range
Pressure setting default
value 0769…0770 1025 (×1) 0…9999 hPa
Pressure setting
temporary value 0771…0772 1026 (×1) 0…9999 hPa
Chemical purge interval 0773…0774 1027 (×1) 10…2880 min
Molecular weight for
ppm
w
calculation
0775…0776 1028 (×0.001) 0…999.999
g/mol
QNH height 0781…0782 1031 (×0.1) -30…3000 m
QFE height 0783…0784 1032 (×0.1) ±30 m
HCP height 0785…0786 1033 (×0.1) ±30 m
Maximum pressure
change 0787…0788 1034 (×0.01) 0…10 hPa
Maximum pressure
difference 0789…0790 1035 (×0.01) 0…10 hPa
If you modify the pressure setting repeatedly, modify the temporary
value at register 0771...0772 (1026) instead of the permanent setting at
register 0769…0770 (1025). Set the temporary value to zero to return to
the default pressure setting.