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Hello Friends,
In one of our projects we have to connect existing fire & gas detectors of the plant to Siemens PCS-7 safety system. Normally we configure 3-wire fire & gas detectors as "Source" type. However, due to some reasons, detectors in this plant have been configured as "Sink" type. According to local Siemens representative, 3-wire sink devices can't be connected to PCS-7 F-AI cards in safety application. Reasons? Not explained.
In my experience it is no issue to connect 2-wire loop powered transmitters (sink type) or four wire separately powered transmitters (source type)to PCS-7. Therefore, I am surprised to know such a limitation for the Siemens F-AI cards.
I will be grateful for your thoughts on this matter.
Regards,
Asok Kumar Hait
In one of our projects we have to connect existing fire & gas detectors of the plant to Siemens PCS-7 safety system. Normally we configure 3-wire fire & gas detectors as "Source" type. However, due to some reasons, detectors in this plant have been configured as "Sink" type. According to local Siemens representative, 3-wire sink devices can't be connected to PCS-7 F-AI cards in safety application. Reasons? Not explained.
In my experience it is no issue to connect 2-wire loop powered transmitters (sink type) or four wire separately powered transmitters (source type)to PCS-7. Therefore, I am surprised to know such a limitation for the Siemens F-AI cards.
I will be grateful for your thoughts on this matter.
Regards,
Asok Kumar Hait
