The TM7BAI4PLA expansion block is a 4 channel Analog Temperature Sensor block with input type J, K, and S thermocouple sensors.
For further information, refer to TM7BAI4PLA Block 4AI thermocouple J/K/S.
Variables can be defined and named in the TM7 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:
|
Variable |
Channel |
Type |
Description |
|---|---|---|---|
|
– |
ModuleOK |
BYTE |
State of the compact I/O and electronic modules |
|
DiagIn |
BYTE |
Status bit associated to each input: o0: OK o1: Error detected |
|
|
Inputs |
Temperature 1 |
INT |
Current value of the input 0 |
|
Temperature 2 |
Current value of the input 1 |
||
|
Temperature 3 |
Current value of the input 2 |
||
|
Temperature 4 |
Current value of the input 3 |
||
|
Terminal Temperature 1 |
INT |
Terminal Temperature of channel 0 |
|
|
Terminal Temperature 2 |
Terminal Temperature of channel 1 |
||
|
Terminal Temperature 3 |
Terminal Temperature of channel 2 |
||
|
Terminal Temperature 4 |
Terminal Temperature of channel 3 |
For further generic descriptions, refer to I/O Mapping Tab Description.
If a sensor type other than J, K 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.
Terminal Temperature (Cold Junction) Compensation
When using thermocouples, it is necessary to measure the temperature at the terminal connections of the TM7BAI4PLA in order to calculate an accurate absolute temperature at the measuring point of the thermocouple. The sensor used to measure the terminal temperature is integrated in the TM7ACTHA thermocouple connector.
NOTE: At least one terminal temperature sensor TM7ACTHA 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.
NOTE: If the J, K and S types are used, you must select the terminal temperature compensation.
The temperature measured at the external reference junction is stored in the I/O area of the TM7BAI4PLA block. The TM7BAI4PLA block calculates the thermocouple temperature internally from the measured voltage and the reference junction temperature value (per channel).
This table provides examples for the possible configurations:
|
TM7ACTHA Connected on the Input Connector |
Description |
|---|---|
|
1 |
The terminal temperature compensation for all 4 channels is performed using the temperature measured on connector 1. |
|
1 and 3 |
The terminal temperature compensation for channels I0 and I1 is performed using the temperature measured on connector 1. The terminal temperature compensation for channels I2 and I3 is performed using the temperature measured on connector 3. |
|
1, 2, 3 and 4 |
The terminal temperature compensation is performed using the temperature measured on the respective connector. |
|
NOTE: For the correspondence between the connectors and channels, refer to Connector and Channel Assignments. |
|
Sensor Type and Channel Deactivation
The block is designed for various sensor types. The sensor type must be specified because of the different adjustment values. To save time, individual channels can be switched off.
This table shows the code corresponding sensor types:
|
Sensor Types |
Digital Value |
Temperature °C (°F) |
Resolution °C (°F) |
|---|---|---|---|
|
Sensor type N |
-2700...2372 |
-270...1300 (-454...2372) |
0.1 (0.18) |
|
Sensor type R |
-500...1664 |
-50...1664 (-58...3027) |
0.1 (0.18) |
|
Sensor type J |
-2200...12000 |
-220...1200 (-364...2192) |
0.1 (0.18) |
|
Sensor type K |
-2700...13720 |
-270...1372 (-454...2501) |
0.1 (0.18) |
|
Sensor type S |
-500...17680 |
-50...1768 (-58...3214) |
0.1 (0.18) |
|
Measurement range of ±32.767 mV |
-32768...32767 |
– |
1 µV |
|
Measurement range of ±65.534 mV |
-32768...32767 |
– |
2 µV |
The table describes the user-defined parameters of the module:
|
Parameter |
Value |
Default Value |
Description |
|---|---|---|---|
|
Filter |
50Hz 60Hz 250Hz 500Hz |
50Hz |
Analog input filter value. |
|
Sensor type |
off J K S N R raw value 1uV raw value 2uV |
off |
Sets the sensor type. The sensor type is applied for all the channels |
|
DisableChannel01 ... DisableChannel04 |
on off |
on |
On: The channel is disabled. NOTE: Selectively disabling of unused channels reduces the electronic module cycle time. |
