Converters: RS232 to RS422 / RS485 I-Loop / Fibre Optic / Isolator

Most industrial computer systems come with standard RS-232 serial ports. Though widely accepted, RS-232 has limited transmission speed, range, and networking capabilities. The RS-422 and RS-485 standards overcome these limitations by using differential voltage lines for data and control signals. The ADAM-4520/4522 converter lets you take advantage of RS-422 and RS-485 on systems originally equipped with RS-232. It transparently converts RS-232 signals into isolated RS-422 or RS-485 signals. You do not need to change your PC’s hardware or your software. The ADAM-4520 lets you easily build an industrial grade, long distance communication system with standard PC hardware. It extends the communication distance by 4000 ft. (1200 m) or increases the maximum number of connected nodes by 32.

Features:

• Automatic RS-485 data flow control
• 3000 VDC isolation protection
• Surge protection RS-485 data line
• Transmission speed up to 115.2 Kbps
• Networking up to 1200 meters (4000 feet)
• Reserved space for termination resistors
• Power and data flow indicator for troubleshooting
• Power requirement: +10 to +30 VDC
• Mounts easily on a DIN-rail, panel or piggyback

Specifications:

Datasheet on ADAM-4520 (pdf, opens in a new tab)

Features:

• Automatic RS-485 data flow control
• Surge protection RS-485 data line
• Transmission speed up to 115.2 Kbps
• Networking up to 1200 meters (4000 feet)
• Reserved space for termination resistors
• Power and data flow indicator for troubleshooting
• Power requirement: +10 to +30 VDC
• Mounts easily on a DIN-rail, panel or piggyback

Specifications:

Datasheet on ADAM-4510 (pdf, opens in a new tab)

Features:

• Automatic RS-485 data fl ow control
• 3000 VDC isolation protection
• Surge protection RS-485 data line
• Transmission speed up to 115.2 Kbps
• Networking up to 1200 meters (4000 feet)
• Reserved space for termination resistors
• Power and data fl ow indicator for troubleshooting
• Power requirement: +10 to +30 VDC
• Mounts easily on a DIN-rail, panel or piggyback

Specifications:

Datasheet on ADAM-4510S (pdf, opens in a new tab)

The ADAM-4521 is an intelligent RS-422/485 to RS-232 converter specifically designed to connect RS-422/485 devices to an RS-232 network. RS-232 is the most common transmission standard. Although widely available on most computer systems, measurement equipment, PLCs, and industrial devices, its transmission speed, communication distance, and especially networking capability are limited due to unbalanced transmission. The ADAM-4521 addressable converter solves this problem and lets you easily build up an RS-485 network with your RS-232 devices by assigning each one an address for easier communication.

Features:

• Automatic RS-485 data flow control
• 1000 VDC isolation protection
• Surge protection RS-485 data line
• Transmission speed up to 115.2 Kbps
• Networking up to 1200 meters (4000 feet)
• Reserved space for termination resistors
• Power and data flow indicator for troubleshooting
• Power requirement: +10 to +30 VDC
• Mounts easily on a DIN-rail, panel or piggyback
• RS-232 and RS-485 can be set to different baud rates
• Watchdog timer function
• Software confi gurable to either addressable or non-addressable mode
• All communication setups stored in EEPROM

Specifications:

Datasheet on ADAM-4521 (pdf, opens in a new tab)

ADAM-4561/4562 allows PC users to connect a serial device to a system that use a USB interface. To attach the ADAM-4561/4562 to a PC, you don’t need to open the chassis or power down your PC. Instantly get one or two extra high-speed RS-232/422/485 ports. The power is derived from the USB port, so there are no power adapters to deal with. This makes the ADAM-4561/4562 especially suitable for modems, printers, POS systems and industrial control devices.

Features:

• Full compliance with USB V1.1 specifications
• RS-232/422/485 port supported
• Transmission speed up to 115.2 kbps
• Isolation protection 3000 VDC provided
• Automatic RS-485 data flow control
• No external power supply necessary; the hub derives its power from the USB port
• Plug & Play installation
• No additional IRQs or I/O ports required
• Hot swap function supported

Specifications:

Datasheet on ADAM-4561 (pdf, opens in a new tab)

IC485S is a 2-way converter for converting RS-232 signals to and from RS-422/RS-485 signals in long-distance applications up to 1200 m (4000 ft.). It supports the connection of up to 32 hubs and features monitoring to confirm the data passing between devices.

Features:

• Data transmission controlled by the RTS signal.
• DCE/DTE selectable.
• Point to point, multidrop, and simplex/duplex link selection.
• Four wire full duplex; two wire half duplex.
• Compact size.
• Cable distance of up to 1200m (4000 ft.).
• Monitor configuration support.
• Supports baud rates up to 115.2kbps.
• OS Support: Windows 2000, Windows XP

Specifications:

IC485SN is a 2-way converter for converting RS-232 signals to and from RS-422/RS-485 signals in long-distance applications up to 1200 m (4000 ft.) – without the need of an external power supply.

Features:

• Data transmission controlled by the RTS signal.
• DCE/DTE selectable.
• Point to point, multidrop, and simplex/duplex link selection.
• Four wire full duplex; Four wire half duplex.
• Compact size.
• Cable distance of up to 1200m (4000 ft.).
• Non powered operation.
• Supports baud rates up to 115.2kbps.
• OS Support: Windows 2000, Windows XP

Specifications:

Opto-isolated (1400VAC), bidirectional, (2 or 4 wire). Works reliably up to 115.2kb/sec. When configured to RS485 mode, the RS485 end normally sits in receive mode, and switches automatically to transmit mode when a character enters the RS232 port.
The baud rate can be set internally with jumpers to ensure that the transmitt mode stays on for long enough for all the bits in the character to be transmitted.

The RS232 side is normally supplied with DB9F on a 45mm ribbon cable, DCE connection (optionally, 25-pin DCE or DTE can be provided).

This side is normally powered from the host (by rectification of the control lines – OK with PC RS232 port).
A pair of screw terminals is provided to power this side if there are problems, e.g. if only 3 wires are being used (RX, TX, Gnd) and there is no +ve voltage from host (9 to 12VDC required).
Two internal LEDs shows transmit and receive data. The RS232 side is opto-coupled to the RS422/485 side.

The RS422/485 side has screw terminal connections inside the end of the case, and to preserve the isolation from the RS232 end of the converter, must be powered with its own isolated 9VDC power supply or mains adaptor (e.g. PAK9 below).
RS485 termination and RS485/RS422 receiver biasing jumpers (see above) are provided. Another jumper can be installed to disable the receiver drive to the RS232 line during an RS 485 transmission.
Plastic Case: 25x50x100mm. Power supply not included.

External power supply, isolated, 9 to 12 VDC is required
PAK9 Plug Pack Mains Adaptor: 240VAC to 9VDC: $20+GST

“Isolated power supply” means that the power supply output + & – terminals are not connected to ground or anything else.

Datasheet on J995X (pdf, opens in a new tab)

Similar to J995X except that the RTS or CTS line on the RS232 side is used to enable the RS485 transmit function.
The RS485 side normally sits in receive mode until the RTS or CTS turns the transmit function on, then off again.
See J995X for Auto-Tx-On (RTS or CTS control not reqd).

The RS232 side has ribbon cable 0.5m, with 25-pin D female connector, (specify male if required).
The ribbon cable can be connected as DTE or DCE. The host powers the RS232 side.
Two internal LEDs shows transmit and receive data.

The RS422/485 side has screw terminal connections, and may be powered with an isolated 9VDC 100mA mains adaptor.
RS485 termination and RS485/RS422 receiver biasing jumpers (see above) are provided. Another jumper can be installed to disable the receiver drive to the RS232 line during an RS 485 transmission.
Plastic Case: 25x50x100mm. Power supply not included.

External power supply, isolated, 9 to 12 VDC is required

PAK9 Plug Pack Mains Adaptor: 240VAC to 9VDC: $20+GST

“Isolated power supply” means that the power supply output + & – terminals are not connected to ground or anything else.

Datasheet on J995A (pdf, opens in anew tab)

The ASeries A440 allows any RS-232 serial device to communicate with any RS-422 serial device. As well
as transferring data the A440 provides one pair of handshaking lines, i.e. DTR/DSR or CTS/RTS for the
control of the data flow.

Simple to use and cost effective, the A440 has been engineered for use in both industrial and commercial
environments.

Features:

• Bi-directional RS-232 <> RS-422 interface conversion in asynchronous mode
• Transient Protection on RS-422 lines
• Supports Xon/Xoff Software Handshaking
• Supports DTR/DSR or CTS/RTS Handshaking
• Switchable DCE/DTE selection for RS-232 port
• Transfer data reliable at up to 64Kbps
• LED indicators for data activity
• Reverse Polatity Protection on power input
• Standard DB25 used for RS-232 and RS-422 interfaces

Specifications:

Datasheet on A440 (pdf, opens in a new tab)

Features:

• Multidrop up to 32 drivers and 32 receivers at distances over 1200 metres
• Non-powered RS-485 operation over distances up to 100 metres
• Supports both 4-wire and 2-wire operation
• Transcient Protection on RS-485 lines
• Screw terminal block used for RS-485 interface
• Standard DB25 used for RS-232 Interface
• Switchable termination resistors for RS-485 port
• Switchable DCE/DTE selection for RS-232 port
• Transfer data up to 115Kbps
• LED indicators for data activity
• Reverse Polatity Protection on power input

Specifications:

Datasheet on A450 (pdf, opens in a new tab)

Features:

• Multidrop up to 32 drivers and 32 receivers at distances over 1200 metres
• Internal jumper settings allow the use of either ‘standard’ or ‘crossed’ Ethernet cables
• Supports both 4-wire and 2-wire operation
• Transient Protection on RS-485 lines
• Transmits data at up to 115Kbps
• Non-powered RS-485 operation over distances up to 100 metres
• Switchable DCE/DTE selection for RS-232 port
• Switchable termination resistors for RS-485 port
• RJ-45 connectors on RS-485 port
• LED indicators for data activity
• Monitor mode allows problem diagnosis on the RS-422/485 bus
• CE and C-Tick Approved
• Very LOW COST – Very BIG FEATURES

Specifications:

Datasheet on A451 (pdf, opens in a new tab)

The CONV485/DB9 allows any PC with standard DB9 male RS-232 COMM Port to run RS-485 devices.

Features:

• Up to 460.8kps
• No External Power Required When Communicating Via a Short Cable with One Device
• Simple Installation, No Need to Shut off PC to Connect
• Nothing to Configure, No Jumpers to Set
• Automatically Adjusts to the Speed of the Data
• Auto RTS Built In
• Plugs Directly into Standard PC RS232

Specifications:

The CONV232/422 allows any PC with standard DB9 male RS-232 Port to communicate with RS-422 and RS-485 devices.

The CONV232/422 can do full duplex peer to peer or one master, one slave communications in RS-422 or RS-485 four wire mode. It can also do two wire RS-485 in a one master, multiple slaves multi-drop configuration when its transmit and receive pins are tied together. In this configuration it echoes data on the RS-232 side.

To operate in 2-wire RS-485 mode the CONV232/422 requires the communications software to control the RTS line. For dedicated two wire RS-485 it is recommended the CONV232/485 be used. Optional External Power is required when communicating with more than two devices or over long transmission lines. External power (+5.5VDC to +16VDC @ 40 mA) can be connected to J2 (RS422 side) pin 8 with return via J2 pin 5.

Features:

• Up to 230.4kbps
• Supports 4 wire RS-422 and 4/2 wire RS-485 full/half duplex communication
• No External Power Required When Communicating Via a Short Cable with One Device
• Simple Installation, No Need to Shut off PC to Connect
• Nothing to Configure, No Jumpers to Set
• Automatically Adjusts to the Speed of the Data
• Plugs Directly into Standard PC RS232

Specifications:

Features:

• The PC485 RS232 to RS485 converter is supplied as a through connector, self contained package.
• Power for the unit is obtained from an IBM PC, or compatible, RS232 port via pins 7 (GND) & 20 (+12V via DTR line). Alternatively the PC485 may be externally powered (9 to 12VDC), see wiring diagram overleaf. The use of an external power source is generally only required when a low power serial card is used in the computer and multiple external units are being addressed or when the serial output does not provide power.
• Baud rates accepted are from 300 to 38400 baud. The converter automatically detects the baud rate being used.
• Connection at the RS232 end is via a 25 way female “D” connector. At the RS485 end the connector is a 25 way male “D” connector.
• Dimensions: 63mm (h) x 56mm (w) x 16mm (d)

Datasheet on AIC PC485 (pdf, opens in a new tab)

The PC422 and PC485 converters are supplied as a through connector, self contained package. The PC485 gives RS232 to RS485 conversion. The PC422 give RS232 to either RS485 or RS422 conversion.

Power for the units is obtained from an IBM PC or compatible RS232 port via pins 7 (GND) & 20 (+12V via DTR line). Alternatively the converters may be externally powered (9 to 12VDC), see wiring diagram overleaf. The use of an external power source is generally only required when a low power serial card is used in the computer and multiple external units are being addressed or when the serial output does not provide power.

Baud rates are from 300 to 38400 baud. The converter automatically detects the baud rate being used.

Connection at the RS232 end is via a 25 way female “D” connector. At the RS485/RS422 ends the connector is a 25 way male “D” connector.

Operation mode and setup selections are made via circuit board links.

Datasheet on AIC RMSI485 (pdf, opens in a new tab)

Opto-isolated, bidirectional, duplex 4-wire or simplex 2-wire I loop.

Supports up to 19Kkbps or more, the supported data speed depends on the line length and quality.

Allows communications up to 1Km or more, with protection from ground currents and accidental connections to high voltage. At the far end the loop can be driven by another STD-990 for isolation at that end, or by a JED 3-slot motherboard power supply. A plug-pack at one end can provide isolated loop power for both directions. Case: 25x50x100mm. Incl 16 way (2×8) cnnctr & ribbon cable.

Interconnects RS232 systems (e.g. a PC) to industrial systems (e.g. PLC) via the 20mA loop standard. Loop current flows in normal state (broken by TX byte, giving a security alarm if line broken (overrun error in communications software).

Isolation rated at 2,500 volts.

Allows multi-dropping with a number of stations connected in series with no special TX ‘‘connect-to-line’’ control software needed.

RX can monitor transmission on line, so verifying transmission is actually happening on the serial network.

This device is designed with five functions in mind:

1. To extend the common RS232 communication standard to distances of 1 Km. or more.
2. To eliminate the problem of ground currents and common mode voltages which can exist between the grounds of electronic equipment separated by distance, especially in industrial or rural-agricultural applications of computers.
3. To totally protect the computing or data logging equipment at both ends of a data link from accidental connection of one or more signal connections between equipment to a high voltage, e.g. 240 volt mains or surges induced by lightning.
4. To allow connection between existing 20-mA interface equipped systems and RS232C connections on JED or other control computers, or PC’s from any source, which usually have RS232C only communication facilities.
5. This device is particularly useful in interfacing Programmable Logic Controllers to PC’s.

Data Path:
RS232 data is fed through a Hewlett Packard HCPL4100 current loop transmitter/isolator. Both terminals of this driver are available on screw terminals on the isolated side. 20 mA loop current passes through the LED of a 20 mA opto-isolator receiver (HCPL4200) and the output is converted back to RS232 data.

The RS232 connections are two rows of stake pins configured in such a way that a ribbon cable can mate directly with a D25 connector as a DTE or DCE device.

Loop Power Supply:
There is no electrical connection between the RS232 and the 20 mA sides, so power for the loop cannot come from the RS232 system. Power for the RS232 output is actually generated from the RS232 signals themselves.

A simple bridge rectifier and filter capacitor with two 20 mA active current sources is provided for the transmit and receive loops. This power supply is normally fed with a 12-15 volt AC or DC signal from a double insulated plug pack which is available as an option. Loop power is normally provided to a system for both transmit and receive loops from one end of a system and so one plug pack can power both loops and is needed at only one end.

Performance is quoted by HP at 20 KBaud data rate at 400 metres. Curves shown on the data sheets show a linear relationship between speed and line length. Induced noise isolation is excellent, even with unscreened cables, although in extreme cases shielded cables could help. However performance is many times better than an RS232
system with the added advantage of complete isolation of the wiring from the computers at either end.

External power supply, isolated, 9 to 12 VDC required

PAK9 plug pack mains adaptor 240VAC to 9VDC: $20+GST

Datasheet on J990 (pdf, opens in a new tab)

Fiber optics transmission offers the benefits of wide bandwidth, immunity to EMI/RFI interference, and secure data transmission. ADAM-4541 can be used as an RS-232/422/485 point-to-point or point-to-mutipoint connection for transmitting and converting full/half-duplex signals and their equivalents within a fiber optic environment. Fiber optics is the perfect solution for applications where the transmission medium must be protected from electrical exposure, lightning, atmospheric conditions or chemical corrosion.

Features:

• Easily mounted on a DIN-rail, panel or piggyback
• Transmission speeds of up to 115.2 kbps
• Optical fibers enable transmission of 2.5 km (measured with 62.5/125 mm)
• Half/Full-duplex, bidirectional transmission mode
• Avoids lightning strikes and EMI/RFI interference
• Prevents damage from electrostatic discharge
• Stable and error-free data transmission
• Automatic internal RS-485 bus supervision
• No external flow control signals required for RS-485
• Transient suppression and over-current protection on RS-422/485 data lines
• Reserved space for termination resistors
• LED for power and data flow indication
• Power requirement: +10 to + 30 VDC

Specifications:

Datasheet on ADAM-4541 (pdf, opens in a new tab)

The 9POP4 isolates and protects RS-232 equipment from lightning surges, accidental high voltage shorts, and ground loops. RS-232 data signals TD, RD, RTS, and CTS are supported at up to 230.4 kbps. Isolation circuits are 2.5 kV rated and protects valuable equipment while maintaining maximum uptime.

Each side of the isolator receives power from a single 12 VDC power supply to maintain the isolation. This powering configuration allows the device to be used in a system with only one power supply, regardless of the power provided by the RS-232 ports.

The isolator uses DB9 male and DB9 female connectors. The female connector is wired as a DCE and should be connected to a DTE port. The male connector is a DTE and should be connected to a DCE port. If you are connecting a DTE to a DTE or a DCE to a DCE, you will need a null modem adapter.

Power supplies recommended and available from B&B Electronics have been tested and certified. Using any other power supply may bypass or degrade the isolation barrier.

Features:

• 2.5 kV Isoaltion
• ESD Protection -15 kV
• Compact IP 30 Plastic Case

Specifications:

Datasheet on ADAM-4541 (pdf, opens in a new tab)