| 摘要 |
The system enables data from analogue or state sensors S1 to S16, four of which may be direct frequency sensors, located in a ZONE 0 (1) environment, to be transmitted by a master transmitter 10 via a fibre optic data link 16 to a master receiver 14. The master receiver is located in a safe environment. The master transmitter comprises a power restrictor unit 18 which has for each data channel a power supply and also a power supply for the printed circuit-board (pcb) of the master transmitter. The master transmitter is located in a ZONE 1 environment. The analogue or state data are voltages which are converted by voltage-to-frequency converters mounted on the pcb and passed to the multiplexer of the master transmitter. The multiplexer feeds the fibre optic link and a demultiplexer at the master receiver reproduces the frequencies. The master receiver re-converts the frequencies to voltage signals. <IMAGE> |
