| 摘要 |
<p>PURPOSE:To reduce the number of optical fibers and to cope with a specification change by connecting control units in a ring form by optical fibers and providing a jumper circuit between the input/output terminals of an electric signal and an input/output buffer. CONSTITUTION:In turning on an operation switch to operate a load 16, a command signal is fed to a parallel electric input terminal 22 of the 1st control unit 2 and given to an input buffer 26 via a jumper circuit 46. A CPU 36 reads the signal via a parallel input circuit 30, a conversion circuit 42 converts it into a serial signal and converted into an optical signal by an electrooptic converter 40 and sent to an optical fiber 8. The sent optical signal is converted into an electric signal by a photoelectric converter 41 in the 3rd control unit 6, the CPU 36 reads the signal to share the signal into a data to the control object load of the unit 6 and a data to be transferred to the 2nd and 1st control units 4, 2. In desiring the input/output relation of the signal between the input/ output terminals, the connection of the jumper in jumper circuits 46, 48 has only to be changed.</p> |
