RS-232 to RS-485 Converter BB-485PTBR with Pluggable Terminal Block Features Converts RS-232 signals to RS-485 signals Extends data communication up to 1219 meters Multi-drop capability - up to 32 receivers per driver Pluggable terminal block for easy wiring Data rate: 300 bps to 115.2 kbps Quick, easy inline installation 12 Vdc power supply required (not included, sold separately) Introduction Ordering Information Model BB-485PTBR converts unbalanced RS-232 signals to balanced, full or half-duplex Model No. Description RS-485 signals. 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 DB9 BB-485PTBR RS-232 to RS-485 Converter with pluggable terminal block connector with pins 2(RD), 3(TD), and 5(SG) supported. Pins 7(RTS) and 8(CTS) are tied together. Also pins 6(DSR), 1(CD), and 4(DTR) are tied together, but not passed through the converter. The RS-485 port has an 8-position pluggable terminal block connector. Accessories Sold Separately BB-SMi6-12-V-ST Power Supply, 12 VDC 6 Watt, Stripped and Tinned, Baud Rate International AC Input, International AC Blades (power supply required) Model BB-485PTBR supports baud rates from 300 bps to 115.2 Kbps. In order to change the baud rate, a resistor and possibly a capacitor must be changed. By looking up the selected baud rate on Table 1 the resistor and capacitor value can be determined. Remove R3 and C7 from the printed circuit board. Place new components in the R2 and Specifications C6 locations. See Figure 1 and 2 for resistor and capacitor locations. Serial Technology RS-232 Connector DB9 female Biasing Resistors RS-485 Connector 8-position, pluggable terminal block The biasing resistors R5 and R7 can also be altered. Model BB-485PTBR comes Data Rate 300 bps to 115.2 kbps standard with 4.7K biasing resistors. To change the value of biasing resistors, remove Power R5 and R7 and replace with new value in locations R4 and R6. See Figures 1 and 2 for Input Voltage 12 Vdc, 100 mA resistor locations. Source External power required (not included, sold separately) Mechanical Termination Resistor The termination resistor is located at R8. A termination resistor can be placed in the R8 Enclosure Plastic location and a jumper wire placed from the terminal location to RD(B). B+B SmartWorx Mounting In-line installation recommends a 100-120 Ohm resistor for termination. See Figure 2 for termination Meantime Between Failures (MTBF) resistor location. MTBF 3857995 hours Calculation Method MIL 217F Parts Count Reliability Prediction Constant Receiver Enable Regulatory Approvals / Standards / Directives The BB-485PTBR is factory-set with the receiver disabled during transmission. It can be Approvals FCC, CE set for constant receiver enable. When R9 is removed, the receiver is in constant receive 2014/30/EU Electromagnetic Compatibility Directive (ECD) mode (four-wire). When R9 is in the circuit it is in half-duplex mode (two-wire). See 2011-65/EU amended by (EU) 2015/863 Reduction of Hazardous CE - Directives Figure 1 for jumper location. Substances Directive (RoHS) 2012/19/EU Waste Electrical and Electronic Equipment (WEEE) EN 55032 Class B Electromagnetic Compatibility of Multimedia Data Line Polarity Equipment Emission Requirments CE - Standards The polarity of the two RS-485 lines must be correct. With no data being sent, the EN 55024 - Information Technology Equipment - Immunity Characteristics RS-232 line should be negative and the RS-485 A terminal should be negative with Limits and Methods of Measurement respect to the B terminal. If your equipment uses a + and - naming scheme, in EN 61000-6-3 + A1 Generic Emission Standard for Residential, Other Standards Commercial and Light-industrial Environments (Class B) most cases, the A line will be connected to the - and the B line will be connected EN 61000-6-2 Generic Immunity Standard for Industrial Environments to the +. BB-USOPTL4-2P BB-USOPTL4-4P 0221ds All product specifications are subject to change without notice. BB-485PTBR 2621dsBB-485PTBR Table 1. Baud Rate Timeouts Figure 1. PC Board Layout - Top Figure 1. PC Board Layout - Bottom Component Replacements for Changing Baud Rate Timeouts Resistor R3 Capacitor C7 Baud Rate Time (ms) (Ohm) (mfd) 300 33.3 330k 0.1 600 16.6 160k 0.1 1200 8.33 820k 0.01 2400 4.16 430k 0.01 4800 2.08 200k 0.01 9600 1.04 100k 0.01 19200 0.520 56k 0.01 38400 0.260 27k 0.01 57600 0.176 16k 0.01 115200 0.0868 8.2k 0.01 Schematic