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®
PowerLogic COM128
RS-232 to RS-485 Converter
Installation and Operation Guide
August 2006
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Conventions Throughout this operation manual, the following methods are used to highlight important information. NOTE Describes important considerations related to a device setup, feature or application. CAUTION Alerts you to a condition which could potentially cause damage to the device or other external equipment. WARNING or DANGER Warns you to avoid conditions that could potentially cause serious personal injury and/or equipment damage.
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Table of Contents COM128 FEATURES ................................................................................................. 1 1 INTRODUCTION ........................................................................................................ 2 2 Physical Features ..................................................................................................... 3 2.1 RS-232 Panel .......................................................................................................
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COM128 Installation and Operation Manual Schneider Electric TM COM128 MULTI-PORT RS-232 TO RS-485 CONVERTER FEATURES • Connects one RS-232 line to four RS-485 buses. � Compatible with short-haul modems and line drivers that are powered by the RS-232 line. • Automatic baud rate detection supporting data rates of 1200, 2400, 4800, 9600, and 19200 baud. � Works directly with M-SCADA, L-SCADA and PowerView software, or with other • DTE or DCE operation allows connection to proprietary software. c
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COM128 Installation and Operation Manual Schneider Electric DTE OR DCE OPERATION 1 INTRODUCTION The COM128 is switch-selectable to act in DTE or The COM128 is used to interface a single RS-232 communica- DCE mode. An RS-232 port is provided for each mode, tions line to up to four RS-485 communications buses. eliminating the need for null-modems. The RS-485 standard restricts each RS-485 bus to supporting In DTE mode, the COM128 supports a CTS-WAIT mode in 32 or fewer devices connected to it. T
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COM128 Installation and Operation Manual Schneider Electric 2.2 RS-485 PANEL 2 PHYSICAL FEATURES The RS-485 panel of the COM128 is illustrated in Figure 2.2.1. 2.1 RS-232 PANEL RS-485 PORTS These four ports connect the COM128 to the four The RS-232 panel of the COM128 is illustrated in Figure 2.1.1. RS-485 buses. Four pluggable 3-pin terminal blocks are provided. DC SUPPLY CONNECTORS These connections allow the COM128 to be powered from a STATUS INDICATORS wide range of DC voltage sources, inc
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COM128 Installation and Operation Manual Schneider Electric Figure 3.1.1 COM128 Configuration Switches 3 CONFIGURATION 3.1 CONFIGURATION SWITCHES SWITCHES These six switches are used to configure the COM128 for the desired operation (see Figure 3.1.1). A switch is ON when it is in the UP position. The following is a description of each mode 1 2 3 4 5 6 of operation. A list of switch settings for the different modes ON follows each mode description. The configuration switches a
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COM128 Installation and Operation Manual Schneider Electric 3.2.2 SPEED COMPENSATION APPLICATION For use with DCE devices that require very accurate baud rate input. Typical uses are with high speed dial up modems. This mode can be programmed to either ignore the Carrier Detect (C
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COM128 Installation and Operation Manual Schneider Electric monitor the RS-232 DTE port for data and continues to pass 3.2.4 RS-485 DATA BUFFERING WITH data to the RS-485 port until there is no data coming into the TRANSMISSION DELAY AFTER RTS RS-232 port. ASSERTION RS-485 TO RS-2
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RS-232 COM128 Installation and Operation Manual Schneider Electric 4.2.2 DIRECT CONNECTION 4 INSTALLATION TO A COMPUTER PORT SELECTION 4.1 DC SUPPLY CONNECTIONS An IBM-compatible PC acts as a DTE (Data Terminal Equipment) RS-232 device. Therefore, the computer’s RS-232 The COM128 is shipped with a 9 VDC adapter which plugs port should be connected to the DCE port on the COM128. into the adapter receptacle. Use only the adapter provided Refer to Figure 4.2.2. with the COM128 for this particula
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RS-232 COM128 Installation and Operation Manual Schneider Electric 4.2.3 CONNECTION TO A MODEM PORT SELECTION A telephone or radio modem typically acts as a DCE RS-232 device. Therefore, the modem’s RS-232 port should be connected to the COM128’s DTE RS-232 port. Refer to Figure 4.2.3. SWITCH SETTINGS To properly communicate with the modem, the COM128 must be configured as a DTE RS-232 device . If the modem requires RTS-CTS handshaking, the RTS/CTS Flow Control function provided by the COM128
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COM128 Installation and Operation Manual Schneider Electric 4.3.3 RECOMMENDED TOPOLOGIES 4.3 RS-485 BUS CONNECTIONS Devices on an RS-485 bus are connected in a point-to-point configuration, with the (+) and (-) terminals of each device 4.3.1 CONVERTOR CONNECTIONS connected to the associated terminals on the next device. This The RS-485 port of the COM128 provides screw down, is illustrated in Figure 4.3.3a. captured wire type terminal blocks that unplug from the main While there are many topol
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COM128 Installation and Operation Manual Schneider Electric RS-232 RS-232 10 Figure 4.3.3a RS-485 Straight-Line and Loop Topologies RS-485 STRAIGHT-LINE TOPOLOGY Last RS-485 Device (End Point) RS-485 PORT RS-485 PORT RS-485 PORT SHLD SHLD SHLD COM128 RS-232 to RS-485 Converter SHLD RS-485 Cable R Termination Resistor T See Section 4.3.3. AWG 22 shielded twisted pair. Overall length: 4000 ft. maximum. PORT D DCE PORT Computer PORT C Last or Modem DTE RS-485 Device PORT PORT B (End Point) RS-485
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COM128 Installation and Operation Manual Schneider Electric CALCULATING OVERALL CABLE LENGTH When determining the overall length of an RS-485 communica- tion straight-line or loop connection, it is important to account for all cable segments. For example, when RS-485 connections to the device are made via an intermediate terminal block (Figure 4.3.2), the lengths of cable between the device and the terminal block must be added to the total cable distance. This length is equal to 2 times dista
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COM128 Installation and Operation Manual Schneider Electric RS-232 RS-232 12 Figure 4.3.3a RS-485 Topologies to Avoid RS-485 STAR CONNECTION RS-485 PORT RS-485 PORT 3-way star SHLD SHLD connection point not allowed COM128 RS-232 to RS-485 Converter RS-485 PORT RS-485 PORT SHLD SHLD DO NOT PORT D DCE PORT Computer CONNECT PORT C or Modem DTE PORT PORT B RS-485 PORT RS-485 PORT PORT A SHLD SHLD RS-485 T-CONNECTION RS-485 PORT RS-485 PORT RS-485 PORT SHLD SHLD SHLD SHLD COM128 RS-232 to RS-485 Con
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COM128 Installation and Operation Manual Schneider Electric 6 TECHNICAL SPECIFICATIONS ELECTRICAL RATINGS FEATURES Isolation: 750 V between RS-232 and RS- Baud Rates Supported: 1200, 2400, 4800, 9600, 19200 485 ports RS-232 Ports: One DTE (Male DB9) Power Supply: Standard: 9 VDC @ 500 mA One DCE (Male DB9) (120 VAC adapter supplied) RS-485 Ports: Four 3-pin, pluggable terminal Alternate: 2-pin pluggable terminal blocks, each with (+), (-), and block accepts shield (SHLD) terminals 9-30 VDC Powe
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COM128 Installation and Operation Manual Schneider Electric -IND OPTION 7 COM128 OPTIONS The -IND option is a universal power supply that allows the COM128 to be powered from any standard international -UNI OPTION voltage and frequency. The power supply is designed for industrial applications where it can be mounted on the wall or The -UNI option is a universal power supply that allows the door of a cabinet. Refer to Figure 7.2.1. COM128 to be powered from any standard international voltage a
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COM128 Installation and Operation Manual Schneider Electric Figure 7.2 Connecting the -IND Power Supply COM128 (see specs for for input range) 1A Slo-Blo IND Power Supply 15 AC (L) AC (N) FG - - + +
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COM128 Installation and Operation Manual Schneider Electric 16 Figure 7.2.1 -IND Option (Industrial P/S)
