Application Information

The Thermo-/Strain-Measurement XMC module TXMC590

is able to measure thermocouples, resistive sensors like

RTD and thermistors, and strain gauges.

It provides 16 non-isolated independent measurement

channels. Each channel consists of a differential analog

input and a differential sensor excitation output. The setup

of the analog in-/outputs, the signal conditioning and the

translation into data values is handled by a microcontroller

with an integrated ADC and current source.

The TXMC590 is suitable for measuring any kind of

ungrounded thermocouples. The cold junction

compensation is done onboard, freeing the user

application from this task. There are three possibilities to

measure the cold junction temperature:

1) A second channel configured as resistive temperature

sensor

2) An onboard I2C temperature sensor

3) An external I2C temperature sensor (not included)

For measuring RTDs ratio metric, there is a high precision

reference resistor onboard. The excitation current is set up

automatically according to the RTD channel settings.

All Strain Gauge types are supported (e.g. quarter, half

and full bridge configurations). However, there is no bridge

completion circuit onboard the TXMC590. Therefore, if

quarter or half bridges are used, these have to be

completed outside of the module. The excitation current is

set up automatically according to the strain gauge channel

settings. As well, every channel can be calibrated and the

measured value is cleared of offset errors.

Each channel can separately be configured for any sensor

type. The measured value is translated into a data value

according to the sensor type, i.e. into temperature or

microstrain. The translation may be set up to provide the

data in a format that allows direct usage without further

calculations. Measurements can be set up to operate

periodically with different time bases or can be triggered

via register access.

The TXMC590 features predefined parameter sets for the

most common sensor types. Additionally, up to 16 userdefined

parameter sets can be persistently stored on

board. These user-defined parameter sets allow

supporting even user defined sensors. A software tool to

build these user-defined parameter sets is part of

TXMC590-SW-xx.

For special customer requirements, the microcontroller is

also programmable via PCI Express which allows

developing and programming special firmware into the

controller.

Software Support (TXMC590-SW-xx) is available for

different operating systems.