RS-232 to RS-485 Converter - surge protection (replaceable fuses)
- Converts RS-232 signals to RS-485 signals
- Built-in surge protection – with replaceable fuses
- Data rate: 9.6k bps
- Easy inline installation
- Automatic Send Data Control
- Extends data communication up to 1219 meters (4000 ft)
- Multidrop capability – up to 32 receivers per driver
- 12 VDC power supply required ( not included, sold separately)
Model BB-485CSP2 converts unbalanced RS-232 signals to balanced, full or half-duplex RS-485 signals. It also provides transient surge protection and fast acting fuses on the RS-485 data lines. RS-485 is an enhanced version of the RS-422 Standard allowing multiple drivers and receivers on a two-wire system.
The RS-232 port has a female DB-25 connector with pins 2 (TD), 3 (RD), and 7 (Signal Ground) supported. Pins 4 (RTS) and 5 (CTS) are tied together, and pins 6 (DSR), 8 (CD), and 20 (DTR) are also tied together. Pins 1 (Frame Ground) and 7 (Signal Ground) are connected straight through to the RS-485 terminal blocks. The 485CSP2 has two LEDs, a Transmit Enable LED to show when the RS-485 driver is enabled, and a Receive Data LED showing data appearing at pin 3 of the RS-232 port. These are very useful for determining if data is getting through the converter. Note that the Transmit Enable LED indicates only that the 485 driver is enabled, data must be present on pin 2 of the 232 side for data to be transmitted out of the 485 side. If no data is present, no data will be transmitted even though the Transmit Enable LED is illuminated. The RS-485 terminal blocks support Transmit Data (A) and (B), Receive Data (A) and (B), Frame Ground, Signal Ground, and 12 VDC input. A 12 VDC external power supply is required(not included, sold separately).
For the protection properties on Model BB-485CSP2 to work, the Frame Ground terminal block or pin 1 on the RS-232 side must be connected directly to a good frame (chassis, green wire, or earth) ground. This must be a low impedance connection for Model BB-485CSP2 to be effective.