The STAHL Resistance Isolator is used in explosive areas to separate PT100 signals for 2-Wire or Three-Wire PT100.
Input is a 3-wire PT100. Output emulates the same three wire signal. But ET200sp must be configured as four wire (see below).
1 DIP Switch Setting[edit | edit source]
Line Fault detection can be switched OFF (wirebreak or short circuit). Since there is no alarm contact, only a red LED goes on...
ADJ1: ON. We are using a 3-Wire PT100 as input.
2 Hardware Connection[edit | edit source]
Input Connection - note that the connection for channel 1 and channel 2 is different:
Output Connection:
File:STahl8190OutputCOnnection.png
Connection to 4xRTD/TC HF Card 6ES7134-6JD00-0CA1:
Here we need to take care. The STAHL device uses diodes in its output circuit. It expects the constant measuring current coming as shown in the above picture "output connection".
Therefore the Siemens card must be configured as 4-wire PT100 and a jumper needs to be set. Otherwise it is not possible to read proper values due to the diodes.
That means:
| Channel 1 | Terminal | Terminal | Terminal | Terminal |
|---|---|---|---|---|
| STAHL | 1 | 2 | 3 | |
| ET200sp | 1 | 5 | 13 | Jumper 1&9 |
| Channel 2 | Terminal | Terminal | Terminal | Terminal |
|---|---|---|---|---|
| STAHL | 5 | 4 | 6 | |
| ET200sp | 2 | 6 | 14 | Jumper 2&10 |
