Computer controlled relay boards.
Relay boards with only relay outputs in SPST, SPDT or DPDT contact configurations, and no other functions on the board.
8 Channel relay boards have the capability to daisy chain units in a string connected to one control method (RS-232, USB, etc.) on the PC or embedded controller. The first unit connected to the PC can be any of the control methods, and the units connected to the daisy chain are RS-232 units, as shown below. The RS-232 units may be 50 feet minimum between units.
Most 1 & 2 channel units are typically connected to only one control method, however one (1 or 2) channel RS-232 board may be the last board on the daisy chain if only a couple extra relays are needed to save cost. This board would be address "A" as this is set in firmware, and the other boards would need to be set to "B" through "P", so each board may be accessed separately.
- Industrial control applications
- Automatic test equipment (ATE)
- Process control systems
- Power switching applications