Can the magnetic proximity switch on the valve be connected directly to the DI channel of the DCS?
Thread Content
This post was last edited by Future_XACY on 2018-5-12 at 14:40. As the title suggests, can a two-wire magnetic proximity switch used to indicate the valve position be connected directly to the DI channels of a DCS? The query voltage for di is 48V. Here is the image; this type of magnetic proximity switch can be connected directly to DI cards. We use Xinhua’s DCS system here.
The operating voltage of magnetic proximity switches must be supplied by a safety barrier; they generally cannot be connected directly to a DI card. A mechanical switch will work.
It depends on the performance parameters of the switch; it’s best to check the switch’s manual to avoid connecting it blindly.
The magnetic switch of p+f seems to be a safety barrier designed specifically for use with it
A DI with built-in power supply should be able to be connected directly to the valve feedback proximity switch; a DI without a power supply is useless when connected to a proximity switch… Mechanical switches generally do not have internal resistance, so it depends on whether the DI has internal power supply or external power supply. It is not highly recommended to use it directly; it’s better to use an intermediate relay for consistency.