Introduction
The CircuitWerkes SRE-16 is a single direction contact transporter & encoder that will accept either contact closures, or DTMF tones and generate a serial data steam that can be used to control remote devices. An SRD-16 is normally required at the receiving end of the cable to decode the serial data. The SRE-16 has 16 optically-isolated inputs, a 6.3mm TRS audio input jack for receiving DTMF tones and a typical D-9 connector for the serial output data.. Whenever one of the inputs is grounded, the corresponding relay closes on the second unit. The SRE-16 can generate serial relay commands by grounding the appropriate input on the D-15 connector or be sending a DTMF tone to the audio input.
Installation
Power is provided by the supplied 9Vdc adapter that comes with your units. If you wish to provide your own power, it must be 7 to 14Vac or 8 to 15Vdc at 250mA or greater. A serial connection between the two units is also required. Serial connections can be standard or null modem types. Jumper JP10 & JP11, lets you choose the type of cable that will connect the two units. If a standard serial connection is used, then The SRE16 should be set for 1-2. If performing a straight through cable test between the SRE-16 and the SRD-16, you will need to set the jumpers on the SRD-16 to the 2-3 positions.
The SRE-16 uses a female D-25 connector for its input connections and the SRD-16 uses a D-37 female for its relay outputs. All of the inputs are optically isolated and are factory defaulted to be internally pulled up. Any SRE-16 input can be activated by connecting its associated pin to ground. When that happens, the corresponding relay output on the SRD-16 should close. The SRE-16's D-25 connector includes the same serial data on pins 2 & 3 that are found on the D-9, so it is possible to make all of the I/O connections to the SRE-16 on one connector. The SRE-16 & SRD-16 support two types of serial cable configurations as described in the "Installation section page three. Both types of wiring configurations are shown below.
