Isolation fence on output detection end of intelligent simulation input communication

The utility model provides an isolating fence on an output detection end of an intelligent simulation input communication which is used for measuring signal of an electrical apparatus in industrial danger place and isolating output. The isolating fence and an intrinsic safe explosion-preventing equipment compose an intrinsic safe explosion-preventing system. The isolating fence comprises: a power supply circuit, an energy limit protective circuit, a signal sampling circuit, a CPU control part, an optical coupling isolation circuit and an input circuit. The isolating fence is characterized in that: a signal input end connects with the energy limit protective circuit, the signal sampling circuit and the CPU control part orderly, then connects with a 489 chip of a 485 output circuit through the optical coupling isolation circuit, the 485 output circuit fully considers various interference and matching for line characteristic impedance on the line, and adopts an absorption loop composed by a voltage-stabiliser tu