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SER-COMi-SI-M

Products Manual
  • SER-COMi-SI-M
  • SER-COMi-SI-M
  • SER-COMi-SI-M
  • SER-COMi-SI-M
SER-COMi-SI-M - 1-Port Opto-isolated RS-232 to RS-422/485 Converter, Metal Case

The SER-COMi-SI-M and SER-COMi-SI-M are used to convert RS-232 signals to RS-422/485 signals. The converters provide instant connectivity to RS-422/485 communication devices for factory automation equipment, multi-drop data collection devices, barcode readers, time clocks, scales, data entry terminals, PC to PC long distance communications (up to 1.3KM) and serial communication in harsh environments.

The SER-COMi-SI-M and SER-COMi-SI-M provide an industrial solution for applications requiring single node or multi-drop communications over short and long distance.

In RS-485 half-duplex mode, the SER-COMi-SI-M and SER-COMi-SI-M also provide automatic data transmit/receive control.

Optical isolation and surge protection are available to SER-COMi-SI-M.

The SER-COMi-SI-M converter is optically isolated with 2000 Volt DC optical isolation. The optical isolation protects your PC from spikes and surges on the RS-422/485 network, by converting the electrical pulse into an optical signal and then changing it back into an electrical pulse. Your computer is well protected, since the surges and spikes cannot cross the optical link. The SER-COMi-SI-M is protected by surge protector to withstand electrostatic discharge and power surges up to 25KV ESD. Surge suppression on all signals prevent from damages caused by lightning or high voltage.

Features

  • Converts RS-232 port to high speed RS-422 / 485 port

  • RS-232 port can be selected to DCE or DTE pin assignment

  • RS-422/485 port is optically isolated with 2000 Volt DC optical isolation

  • RS-422/485 port is protected by surge protector on all signal lines to withstand electrostatic discharge and power surges up to 25KV ESD

  • Data rates: 300 bps to 1M bps

  • RS-232 Connector: One DB-9 female connector

  • RS-422/485 Connector: One DB-9 male connector and one 5-pin terminal blocks

  • Auto transmit/receive control for 2-wire RS-485 half-duplex operation

  • Termination and Bias resistors installed on-board

  • RS-422 data signals: TX-, TX+, RX+, RX-, GND, RTS-, RTS+, CTS+, CTS-

  • RS-485 data signals: TX-, TX+, RX+, RX- (4 wire), and data-, data+ (2 wire)

  • Monitor LEDs of TxD, RxD indicating port status

  • Wide input power range: 9V DC to 48V DC

  • Includes an external switching terminal power adapter

    SER-COMi-SI-M

Serial Interface
RS-232 Connecto One DB-9 female connector
RS-422/485 Connector One DB-9 male connector and one 5-pin terminal blocks
   
Serial Line Protection
ESD Protection 25KV
Optical isolation 2000V DC
   
Serial Port Speed
Baudrate 300 bps to 921.6k bps
   
Serial Signals
RS-422 TxD-(A), TxD+(B), RxD+(B), RxD-(A), GND, RTS-(A), RTS+(B), CTS+(B), CTS-(A)
RS-485-4 wire TxD-(A), TxD+(B), RxD+(B), RxD-(A), GND
RS-485-2 wire Data-(A), Data+(B), GND
   
Power Supply
Input Self-powered
Power adapter of 12VDC, 1A, terminal type
   
Mechanical
Chassis SECC metal chassis with DIN rail bracket
   
Environmental
Operating Temperature 0 to 55 °C (32 to 131 °F)
Operating Humidity 5 to 95% RH
Storage Temperature -20 to 75 °C (-4 to 167 °F)
Safety Approvals CE, FCC
RS-422 & RS-485 DB9 Male Connector Pin-outs
RS-422 DB9 Male
    RS-422 Signal Pin-outs of DB-9 Male
  Pin Signal  
  1 Tx- (A)  
  2 Tx+(B)  
  3 Rx+(B)  
  4 Rx- (A)  
  5 GND  
  6 RTS- (A)  
  7 RTS+(B)  
  8 CTS+(B)  
  9 CTS- (A)  
 
RS-485 DB9 Male
    RS-485 4-Wire (Full duplex) Signal Pin-outs of DB-9 Male Connector
  Pin Signal  
  1 Tx- (A)  
  2 Tx+(B)  
  3 Rx+(B)  
  4 Rx- (A)  
  5 GND  
 
    RS-485 2-Wire (Half duplex) Signal Pin-outs of DB-9 Male Connector
  Pin Signal  
  1 Data- (A)  
  2 Data+(B)  
  5 GND  
 
RS-422 Terminal Block
    RS-422 Signal Pin-outs of Terminal Block
  Pin Signal  
  1 Tx- (A)  
  2 Tx+(B)  
  3 Rx+(B)  
  4 Rx- (A)  
  5 GND  
 
RS-485 Terminal Block
    RS-485 2-Wire (Half duplex) Signal Pin-outs of Terminal Block
  Pin Signal  
  1 Data- (A)  
  2 Data+(B)  
  5 GND  
 
    RS-485 4-Wire (Full duplex) Signal Pin-outs of Terminal Block
  Pin Signal  
  1 Tx- (A)  
  2 Tx+(B)  
  3 Rx+(B)  
  4 Rx- (A)  
  5 GND  
 

RS-422 Signal Wiring

    Point-to-Point 4 Wire Full Duplex

SER-COMi-SI-M                                    RS-422 Device

    RS-422 with Handshaking

SER-COMi-SI-M                                   RS-422 Device

RS-485 Signal Wiring

    Point-to-Point 4-Wire Full Duplex

SER-COMi-SI-M                               RS-485 Device

    Multidrop RS-485 2-Wire Half-duplex

SER-COMi-SI-M                               RS-485 Device

Setting of RS-232 to DCE or DTE

Inside the converter, there are two 2x3 (JP1, JP2) header blocks which are jumpered to
select the RS-232 port pin assignment to DCE or DTE.

  Jumper Function  
  JP1
1-3 2-4
JP2
1-3 2-4
RS-232 port assigned to DCE (Data Communications Equipment).(See Figure 1)  
  JP1
3-5 4-6
JP2
3-5 4-6
RS-232 port assigned to DTE (Data Terminal Equipment).(See Figure 2)  
The factory default setting is DCE

Fig 1. DCE setting

Fig 2. DTE setting

Termination and Biasing Option Configuration

Termination Resistor

When transmitted signals arrive at the end of a cable, they get reflected. They travel on the cable some more times, which is called ringing. This can cause false reading of transmitted data. For long cables termination resistors are required. These increase the damping of reflection. The value of the termination resistor must match the impedance of the cable, typically 120 ohms.

Biasing Resistors

In RS-485 operation, the sender must activate the transmitter before sending data, and deactivate it when all data is sent. At times when no devices send data all transmitters are inactive. As the result the data lines are floating, and the differential voltage is undefined. It may happen the next data is not correctly recognized, because the change from undefined to data signals is not detected. To avoid such problems the data lines should be polarized by biasing resistors. The biasing resistors must not be too small, typical biasing resistors are 750 ohms in high and low level.

Jumper Setting to Enable Termination & Biasing Resistors

Inside the converter, there is one 7 x 3 (21 pins, Fig. 3) header blocks which are jumpered to enable Tx, Rx, CTS 120 Ohm termination resistors and Rx, Tx 750 Ohm biasing resistor. You will need to open up the metal case and set the jumpers to RS-422 mode or RS-485 mode as per the requirements of your application. Termination and biasing settings are listed as follows:

Fig. 3 Termination and Biasing resistors setting
  Jumper Function  
  1-2 enable
2-3 disable
Tx+/- Termination of 120 Ohm.
This jumper should always be populated for RS485 Half-Duplex mode.
 
  4-5 enable
5-6 disable
Pull-up Tx+ to VCC by 750 Ohm Bias resistor.
This jumper should be populated for pull-up Tx+.
 
  7-8 enable
8-9 disable
Pull-down Tx- to GND by 750 Ohm Bias resistor.
This jumper should be populated for pull-down Tx-.
 
  10-11 enable
11-12 disable
Rx+/- Termination of 120 Ohm.
This jumper should always be populated for RS-422 and RS-485
Full-Duplex mode.
 
  13-14 enable
14-15 disable
Pull-up Rx+ to VCC by 750 Ohm Bias resistor.
This jumper should be populated for pull-up Rx+.
 
  16-17 enable
17-18 disable
Pull-down Rx- to GND by 750 Ohm Bias resistor.
This jumper should be populated for pull-down Rx-.
 
  19-20 enable
20-21 disable
CTS Termination of 120 Ohm.
This jumper should always be populated for RS-422 mode.
 

Note: Sometimes, when operating in RS-422 or RS-485, it is necessary to configure
termination and biasing of the data transmission lines. Generally this must be done in the cabling, since this depends on the installation of connections. Before applying the option, check your cable specification for proper impedance matching.

Biasing of data lines must only occur at a single point anywhere in the cabling. SER-COMi-SI-M and SER-COMi-SI-M provide biasing for ease of installation. Please be sure to disable this inside the unit, if your cabling already provides biasing.

Termination must not be installed in the middle of the cable. It is only permitted at both ends. Since a computer controlled serial port is almost always at one end of the cable, termination is enabled by default.