S.I. Tech, Inc. Optical Mini Multidrop Bit-Driver® 2139

S.I. Tech model 2139 is a mini multidrop optical Bit-Driver that contains three fiber ports. The upstream and downstream fiber ports repeat data through the 2139 multidrop and drop/insert data on the RS-232 fiber port. The RS-232 fiber port inserts data onto upstream fiber port only and gets data dropped from upstream fiber port only. The downstream fiber port only sends/receives data from the upstream fiber port. Having fiber on all three ports provide total optical isolation to attached equipment.