MA1044 MAQ20-RTD31/-RTD41 Hardware User Manual
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Once a range selection is made it can be saved to EEPROM by writing a 0 to register 119. Standard
Reset does not affect the setting in volatile memory. Reset-to-Default will clear the setting in volatile
memory and reset the ranges to the default values. Settings stored to EEPROM are not affected by
Standard Reset or Reset-to-Default. Module power cycle will restore range settings from EEPROM.
Example:
A MAQ20-RTD31 module with serial number 1234567-89 is installed in a system and has
been assigned a Registration Number of 2. Set channels 0 and 1 for a PT100 sensor
measuring -200°C to +200°C, set channels 4 and 5 to measure a 5k
Ω potentiometer, and
disable channels 2 and 3. Obtain the current readings in counts and convert these to
Engineering units.
The MAQ20-RTD31 module with s/n 1234567-89 has an address offset of 2000 * 2 = 4000
The default module configuration is all channels enabled and all channels set for a PT100 sensor
measuring -200°C to +850°C. The Range Table shows that Range 1 is PT100 -200°C to +200°C in
and Range 3 is potentiometer 0
Ω
to 5000Ω in. Range information is also stored in registers at
Addresses 1700
– 1800 for user read back if desired.
Write to register address 4000+100 = 4100 a data value of 1 to set Ch 0 to PT100, -200°C/+200°C
Write to register address 4000+101 = 4101 a data value of 1 to set Ch 1 to PT100, -200°C/+200°C
Write to register address 4000+104 = 4104 a data value of 2 to set Ch 4 to potentiometer, 5k
Ω
Write to register address 4000+105 = 4105 a data value of 2 to set Ch 5 to potentiometer, 5k
Ω
Write to register address 4000+142 = 4142 a data value of 0 to disable Channel 2
Write to register address 4000+143 = 4143 a data value of 0 to disable Channel 3
Read from register address 4000+1000 = 5000 the data from Channel 0
Read from register address 4000+1001 = 5001 the data from Channel 1
Read from register address 4000+1004 = 5004 the data from Channel 4
Read from register address 4000+1005 = 5005 the data from Channel 5
If the data read from Channel 0 is -133 counts and the data read from Channel 4 is 3120 counts,
the input signals are:
Ch 0: -133 counts * (200°C - -200°C) / (4016 counts - -4016 counts) = -6.6°C
Ch 4: 3120 counts * (
5000Ω - 0Ω) / (4016 counts - 0 counts) = 3884.5Ω
