Description A little background...Historically, Optec's products and instruments have used a serial communication protocol to communicate with an external computer. Optec's RS-232 protocol implementation is a 3-wire subset of the official RS-232 specification. Over the years, our implementation has proven to be quite robust. Our latest cable product is a unique 3-wire RJ-12 to USB direct connect Serial/USB Cable designed especially for the TCF-S, IFW, and Pyxis rotator. "Reverse" Cables and USB/Serial Cables The TCF-S and TCF-Si focuser family, FocusLynx controller, IFW filter wheels, and Pyxis camera field rotators each use a modular RJ12 connector directly on the instrument or on a separate control box. These female RJ12 sockets all use the same pin configuration with RX, TX, and GROUND ports (see inset at lower left) which has historically been connected through a separate "Reverse" cable and Serial Port Converter. The simple flat "Reverse" cable was engineered such that any observatory user or installer with a standard telephone cable crimper could easily fabricate cables after fishing the flat 6-wire cable through mount, pier and floor conduits. A pre-wired "serial port converter" could be supplied for such installations making for an easy job of wiring up the observatory. Unfortunately, with the disappearance of dedicated DB-9 serial ports on today's computers, a third item, the USB-to-Serial Converter became necessary. This configuration has lead to a 3-piece communication wiring scheme that was less than optimal. The Optec solution is the USB/Serial cable with an integrated USB converter. Currently all new Optec products include a 6-ft. USB/Serial cable as standard. Our other, longer cable lengths of 12, 25, and 50-ft. continue to be very popular and are available from stock. When requested, we can fabricate a custom length USB/Serial cable for any installation. Complete USB/Serial Cables: New Serial Cables with Integrated USB Converters Recent advancements in USB-to-Serial converter technologies has allowed Optec to offer a single Serial / USB cable in place of the 3-piece configuration. These cables are available in standard lengths of 6, 12, 25, and 50-ft. Because the cable is standard RS-232 level on the long side of the cable, the 5-meter (16-ft.) length restriction for USB does not apply. 19670 Optec USB/Serial Communication Cable, 6-ft. length 19672 Optec USB/Serial Communication Cable, 12-ft. length 19673 Optec USB/Serial Communication Cable, 25-ft. length 19674 Optec USB/Serial Communication Cable, 50-ft. length 19675 Optec USB/Serial Communication Cable, custom length $45 plus $1 per foot. Original Style "Reverse" Cable: Our original "Reverse" cables are still available in standard and custom lengths. Most are in stock for immediate shipment. #17671 - 6-ft. Reverse Serial Cable - List Price: $10 #17672 - 12-ft. Reverse Serial Cable - List Price: $15 #17673 - 25-ft. Reverse Serial Cable - List Price: $25 #17674 - 50-ft. Reverse Serial Cable - List Price: $30 "Null Modem" Serial Cables The SSP photometer line and Perseus 4-port Instrument Selector each use a standard DB9 connector with standard RX, TX, and GND ports connected. A "Null Modem" serial cable is required to make the connection to a PC's 9-pin DB9 serial port. Available in lengths from 6-ft (2m) to 25-ft (8m) these serial cables feature a female DB9 connector on both end with locking thumbscrews. #17154 - 6-ft. Null Serial Cable - List Price: $20 #17155 - 10-ft. Null Serial Cable - List Price: $30 #17156 - 15-ft. Null Serial Cable - List Price: $40 #17157 - 25-ft. Null Serial Cable - List Price: $50