485BAT3-0812-1/2 2003 by B&B Electronics. All rights reserved. Model 485BAT3 Battery Powered RS-232 to RS-422/485 Converter Model 485BAT3 features power versatility, making it perfect for field testing solutions. It converts unbalanced RS-232 signals to balanced RS-422 or RS-485 signals. RS-485 is an enhanced version of the RS-422 standard, allowing multiple drivers and receivers on a two-wire system. Power The 485BAT3 can be powered in three ways: batteries, port powered, or power supply. Use the battery power option when you have a low power RS-232 port (found on many laptops today) or no handshake lines or when it is inconvenient to use a power supply. Install 2 AAA batteries (not included) and put the Battery On/Off switch in the ON position. The 485BAT3 will draw as much power as possible from the RS-232 port and get any additional current necessary from the batteries. If you have a full power port and all your handshake lines, turn off your battery switch. This allows you to run fully port powered and saves your batteries for emergencies. NOTE: The Battery On-Off switch on the 485BAT3 is used for conserving battery life. It does not turn on and off all power to the unit. For your convenience there is the option to use a stripped and tinned +12VDC power supply. Simply attach it to the terminal blocks and plug it in. Switches In addition to the Battery On/Off switch described in the Power section above there is a 2-position dipswitch on the top of the 485BAT3. The position of these switches determines whether the signals on the terminal blocks are RS-422 or RS-485. With both switches in the Off position the unit will act as a full duplex RS-232 to RS-422 converter. With both switches in the On position, the unit acts as a half-duplex R-232 to RS-485 converter capable of multidropping on the RS-485 side. When the RS-422/RS-485 switch is in the RS-485 position, the 485BAT3 uses a bit-wise enable method to control the RS-485 driver. This means that the RS-485 driver is enabled with each high bit transmitted. This method requires no handshake control to activate and deactivate the driver. When the RS-422/RS-485 switch is in the RS-422 position the driver is constantly enabled. The Echo On/Off switch controls the RS-485 receiver. When it is in the On position the receiver is constantly enabled. When this switch is in the Off position the receiver is enabled only when the RS-485 driver is disabled for use in 2-wire mode to prevent the transmitted data from echoing back on the RS-232 side. Connections Table 1: RS-232 Pinouts The RS-232 port has a female DB9 connector with pins 2 (RD), 3 (TD), and 5 (Signal Ground) supported. Pins 7 (RTS) and 8 (CTS) are tied together, and RS - 232 Pinouts Description pins 6 (DSR), 1 (CD), and 4 (DTR) are also tied together. Any incoming data 1 DCD lines in either the high or low state are used to port power the 485BAT3. The 2 RD more handshake lines available, the longer the battery life, and the more likely the unit can be totally port powered. Table 1 shows the RS-232 pin outs. 3 TD 4 DTR The RS-485 port uses terminal blocks for easy field wiring. TD A(-), TD B(+), 5 GND RD A(-), RD B(+), and Signal Ground lines are supported. Figure 1 shows how 6 DSR to interconnect two RS-485 converters using two wires. Figure 1 shows how to 7 RTS interconnect two RS-422 converters using four wires. Terminating resistors are optional. They should be used only on long length runs or at high baud rates. 8 CTS These resistors should match the impedance of the cable being used, which is normally about 120 Ohms. Up to 32 receivers can be driven by any one RS-485 driver, allowing you to put together large systems with many drop points. If you are using termination resistors, they should be located at opposite ends of the system. www.bb-elec.com orders bb-elec.com support bb-elec.com International Office: 707 Dayton Road PO Box 1040 Ottawa, IL 61350 USA 815-433-5100 Fax 433-5104 European Office: Westlink Commercial Park Oranmore Co. Galway Ireland +353 91 792444 Fax +353 91 792445 PRODUCT INFORMATION B&B ELECTRONICS 485BAT3-0812-2/2 2003 by B&B Electronics. All rights reserved. Figure 1: Typical RS-485 Two-Wire Setup Figure 1: Typical RS-422/485 Four-Wire Setup 4 Wire Device 485BAT3 RD B+ 2 Wire Device TD B+ Data B+ Rt Rec. TD B+ RD A- TD A- Rt Rec. Data A- TD A- Enable Enable TD B+ RD B+ RD B+ Rt Dr. TD A- Dr. RD A- RD A- GND Rt GND GND GND DECLARATION OF CONFORMITY Manufacturers Name: B&B Electronics Manufacturing Company Manufacturers Address: P.O. Box 1040 Specifications 707 Dayton Road Ottawa, IL 61350 USA Dimensions: 3.6 x 2.6 x 1.1 in. (9.0 x 6.5 x 2.8 cm) Model Numbers: 485BAT3 Data Rate: Up to 115.2 kbps Description: RS-232 to RS-422/485 Converter Connectors: RS-232: DB-9 female (DCE) Type: Light industrial ITE equipment RS-485: Terminal blocks Application of Council Directive: 89/336/EEC Standards: EN 55022 Power Supply Options: Port-powered EN 61000-6-1 12 VDC 100mA EN 61000 (-4-2, -4-3, -4-4, -4-5, -4-6, -4-8, -4-11) 2 AAA batteries (not included) 7 hours fully loaded with no port power available 100 to 250 hours typical Battery Life: Two-channel device (transmit and receive only) Robert M. Paratore, Director of Engineering www.bb-elec.com orders bb-elec.com support bb-elec.com International Office: 707 Dayton Road PO Box 1040 Ottawa, IL 61350 USA 815-433-5100 Fax 433-5104 European Office: Westlink Commercial Park Oranmore Co. Galway Ireland +353 91 792444 Fax +353 91 792445 PRODUCT INFORMATION B&B ELECTRONICS