Configuration registers - GMP251 - GMP80P

GMP251 and GMP80P User Guide
Document code
M211799EN
Revision
K
Language
English
Product
GMP251
GMP80P
Document type
User guide
CAUTION Default power-up values (registers 513–519) are written into non-volatile EEPROM memory. The EEPROM memory implementation has a limit of 30000 writes, and is intended to be used only when saving long-term or permanent configurations. Use the volatile memory (registers 521–527, values cleared on power-up) for non-permanent configurations (for example, if the probe is used in a system that regularly updates the compensation values).
Modbus configuration data registers (writable)
Register number Address Description Data format Unit / Valid range
513 0x0200 Power-up value for pressure compensation 32-bit float hPa

500–1100 hPa

Operating <1.5 bar

(Init/default: 1013.25)
515 0x0202 Power-up value for temperature compensation 32-bit float °C

−40 … +80 °C

(Init/default: 25)
517 0x0204 Power-up value for humidity compensation 32-bit float %RH

0–100 %RH

(Init/default: 0)
519 0x0206 Power-up value for oxygen compensation 32-bit float %O2

0–100 %O2

(Init/default: 0)
521 0x0208 Volatile (value cleared at probe reset) pressure compensation 32-bit float 500–1100 hPa

(Init copied from power-up value)
523 0x020A Volatile (value cleared at probe reset) temperature compensation 32-bit float −40 … +80 °C

(Init copied from power-up value)
525 0x020C Volatile (value cleared at probe reset) humidity compensation 32-bit float 0–100 %RH

(Init copied from power-up value)
527 0x020E Volatile (value cleared at probe reset) oxygen compensation 32-bit float 0–100 %O2

(Init copied from power-up value)
769 0x0300 Modbus address 16-bit integer 1–247 (default: 240)
770 0x0301 Serial speed enum 4800–115200

0 = 4800

1 = 9600

2 = 19200

3 = 38400

4 = 57600

5 = 115200

(default: 2 (19200))
771 0x0302 Serial parity enum

0 = None

1 = Even

2 = Odd

(default: 0 (None))
772 0x0303 Serial stop bits 16-bit integer 1–2

(default: 2)
773 0x0304 Pressure compensation mode enum

0 = Off

1 = On

(default: 1 (On))
774 0x0305 Temperature compensation mode enum 0 = Off

1 = Given

2 = Measured

(default: 2 (Measured))
775 0x0306 Humidity compensation mode enum 0 = Off

1 = On

(default: 0 (Off))
776 0x0307 Oxygen compensation mode enum 0 = Off

1 = On

(default: 0 (Off))
777 0x0308 CO2 filtering factor 16-bit integer 0–100

(default: 100 (no filtering)).

For information on setting the filtering factor, see Filtering Factor on page 1.
To apply an accurate relative humidity compensation (775), you must also enable temperature compensation (774) and pressure compensation (773).