Hardware Connectivity

The 485SD9RJ is a port-powered, half-duplex RS-232 to RS-485 converter with send data control. The unit converts TD and RD RS-232 lines to balanced RS-485 signals and supports two-wire RS-485 communications only. The converter is powered from the RS-232 handshake lines, RTS, CTS and DTR, DSR, CD. The handshake lines are looped back on each other and can be in either state. No handshake change is necessary so no software is required to control the lines. The RS-485 driver is enabled with each bit of data. The RS-485 receiver is disabled when the driver is enabled and is enabled when the driver is disabled. This prevents data from being echoed back into the RS-232 device. The RS-232 side has a DB-9 female connector. The RS-485 side has a six-position RJ11 connector.

The 485TBLED converts unbalanced, full-duplex RS-232 signals to balanced, full or half-duplex RS-422 or RS-485 signals. RS-485 is an enhanced version of the RS-422 Standard. It allows multiple drivers and receivers on a two-wire or four-wire system.

The RS-232 port, configured as a DCE port, has a female DB25 connector with pins 2 (TD input), 3 (RD output), 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 RS-485 terminal blocks support Transmit Data (A-) and (B+), Receive Data (A-) and (B+), Frame Ground, Signal Ground, and +12 VDC input. See Schematic.

These compact USB to Asynchronous Serial RS-232 and
RS-485 mini-converters allow you to add a serial port to your USB only PC. They are perfect connecting to a remote device to gather data or upload a program. USB 2.0 compatibility makes installing them on your PC easy. Versions are available with DB9 connectors and Terminal Blocks for quick wiring. We support RS-232, RS-485
(2-Wire) and RS-485 (4-Wire) protocols. Need 5 Volt and 3.3 Volt TTL? We even have a converter for that. Our driver software supports operating systems up to Windows 7 with 32 and 64 bit support.

Isolates and converts RS-232 signals into RS-422 / RS-485 signals and vice versa. Unlike other converters, external software is not required to control data flow. The RS-232 input is wired for DCE and interfaced through a female DB25 or DB9 connector. RS-422 or RS-485 signals are connected to a removable terminal block. External power is applied to separate removable terminal block. A 10 - 48 VDC power supply (not included) is required.

Wide temperature and power ranges make B&B Electronics isolated converters ideal for your harsh duty applications. Automatic Send Data Control, Modbus compatible. The RS-232 side has both a terminal block connector and a DB9 female connector; the RS-485 side has a terminal block. Requires external power supply not included.