TM5SAI2TH and TM5SAI6TH

Introduction

The TM5SAI2TH and TM5SAI6TH expansion electronic modules are Analog Temperature Sensor with 2 and 6 Inputs respectively.

For further information, refer to the Hardware Guide:

Analog Inputs

The converted analog values are output by the electronic module in the registers. The sensor type configured affects the value ranges.

Raw Value Measurement

If a sensor type other than J, K, N, or S is used, the terminal temperature must be measured on at least one input. Based on this value, the user must perform a terminal temperature compensation.

Timing Setting

The timing setting for data acquisition is made using the converter hardware. All switched on inputs are converted during each conversion cycle. A terminal temperature measurement also takes place.

If an input is not necessary, it can be deactivated by setting the channel to Off, thereby reducing the refresh time. The measurement of the terminal temperature is deactivated.

Conversion Time

The conversion time depends on the number of channels used. For the formulas listed in the table, 'n' corresponds to the number of channels that are activated.

Terminal Temperature (Cold Junction) Compensation

General information

When using thermocouples, it is necessary to measure the temperature at the terminal connections of the TM5SAIxTH in order to calculate an accurate absolute temperature at the measuring point of the thermocouple.

NOTE: At least one terminal temperature sensor is required to determine the temperature measured by the connected thermocouples. Otherwise, a value of 7FFF hex is calculated for all the connected thermocouples.

The accuracy of the temperature measurement of the connected thermocouples is a function of the number of terminal temperature sensors connected to the block.

A terminal temperature compensation junction is useful for the following applications:

oWhen there is a large distance between the controller and point of measurement.

oTo increase precision.

Bridging large distances

When there is a large distance between the controller and the point of measurement, use a terminal temperature compensation junction. The thermocouple voltage is supplied via copper cable from the terminal temperature compensation junction to the terminal on the TM5SAIxTH. The temperature measured at the terminal temperature compensation junction is stored in the I/O area of the TM5SAIxTH electronic module. The TM5SAIxTH electronic module calculates the thermocouple temperature internally from the measured voltage and the reference junction temperature value (per channel).

Increased precision 

To increase the precision, use a terminal temperature compensation junction. The construction of the terminal temperature compensation junction is the same as described above. The installation of a terminal temperature compensation junction is especially helpful in the following cases:

oThere is a slice next to the TM5SAIxTH that requires more than 1 W.

oThere is no slice next to the TM5SAIxTH.

oWith strongly fluctuating ambient conditions (draft, temperature).

NOTE: If the J, K, N and S types are used, you must select the external compensation.

Sensor Type and Channel Deactivation

The electronic module is designed for various sensor types. The sensor type must be specified because of the different adjustment values. The default setting for all channels is ON. To save time, individual channels can be deactivated.

This table shows the code corresponding sensor types:

TM5 Module I/O Mapping Tab

Variables can be defined and named in the TM5 Module I/O Mapping tab. Additional information such as topological addressing is also provided in this tab.

This table describes the I/O mapping configuration:

For further generic descriptions, refer to User-Defined Parameters Tab Description.

NOTE: The channel 2...5 parameters are not available for the TM5SAI2TH.

User-Defined Parameters Tab

This table describes the TM5SAI2TH and TM5SAI6TH user-defined parameters configuration: