
ODW-720-F1
Fibre Optic Modem
Industrial Converter RS-232 to Fibre Optic Link
Point to Point applications
General information
Legal information
The contents of this document are provided “as is”. Except as required by applicable law, no warranties of any kind are made in relation to the accuracy and reliability or contents of this document, either expressed or implied, including but not limited to the implied warranties of merchantability and fitness for a particular purpose. Westermo reserves the right to revise this document or withdraw it at any time without prior notice.
Under no circumstances shall Westermo be responsible for any loss of data or income or any special, incidental, and consequential, or indirect damages howsoever caused. More information about Westermo can be found at www.westermo.com
Safety and Regulations
Warning signs are provided to prevent personal injury and/or damages to the product.
The following levels are used:
Level of warning | Description | Consequence personal injury | Consequence material damage |
![]() | Indicates a potentially hazardous situation | Possible death or major injury | Major damage to the product |
![]() | Indicates a potentially hazardous situation | Minor or moderate injury | Moderate damage to the product |
![]() | Provides information in order to avoid misuse of the product, confusion or misunderstanding | No personal injury | Minor damage to the product |
![]() | Used for highlighting general, but important information | No personal injury | Minor damage to the product |
Before installation:
Read this manual completely and gather all information on the product. Make sure that you understand it fully. Check that your application does not exceed the safe operating specifications for this product.
![]() | WARNING – SAFETY DURING INSTALLATION The product must be installed by qualified service personnel and built into an apparatus cabinet or similar, where access is restricted to service personnel only. |
![]() | WARNING – HAZARDOUS VOLTAGE Do not open an energized product. Hazardous voltage may occur when connected to a power supply. |
![]() | WARNING – PROTECTIVE FUSE It must be possible to disconnect manually from the power supply. Ensure compliance to national installation regulations. Replacing the internal fuse must only be performed by Westermo qualified personell. |
![]() | CAUTION – CLASS 1 LASER PRODUCT Do not look directly into a fiber optical port or any connected fiber, although the product is designed to meet the Class 1 Laser regulations and complies with 21 CFR 1040.10 and 1040.11. |
![]() | CAUTION – ELECTROSTATIC DISCHARGE (ESD) Prevent electrostatic discharge damages to internal electronic parts by discharging your body to a grounding point (e.g. use a wrist strap). |
![]() | CAUTION – HANDLING OF SFP TRANSCEIVERS SFP transceivers are supplied with plugs to avoid contamination inside the optical port. They are very sensitive to dust and dirt. If the fiber is disconnected from the product, the protective plugs on the transmitter/receiver must be connected. The protective plugs must be kept on during transportation. The fiber optics cables must be handled the same way. |
Care recommendations
Follow the care recommendations below to maintain the full operation of the product and to fulfill the warranty obligations:
- Do not drop, knock or shake the product. Rough handling above the specification may cause damage to internal circuit boards.
- Use a dry or slightly water-damp cloth to clean the product. Do not use harsh chemicals, cleaning solvents or strong detergents.
- Do not paint the product. Paint can clog the product and prevent proper operation.
If the product is used in a manner not according to specification, the protection provided by the equipment may be impaired.
If the product is not working properly, contact the place of purchase, nearest Westermo distributor office or Westermo technical support.
Cleaning of the optical connectors
In the event of contamination, the optical connectors should only be cleaned by the use of recommended cleaning fluids and correct cleaning equipment.
Recommended cleaning fluids:
- Methyl-, ethyl-, isopropyl- or isobutyl-alcohol
- Hexane
- Naphtha
Product disposal
This symbol means that the product shall not be treated as unsorted municipal waste when disposing of it. It needs to be handed over to an applicable collection point for recycling electrical and electronic equipment. By ensuring this product is disposed of correctly, you will help to reduce hazardous substances and prevent potential negative consequences to both environment and human health, which could be caused by inappropriate disposal.
Declaration of Conformity
Hereby, Westermo declares that this product is in compliance with applicable EU directives and UK legislation. The full declaration of conformity and other detailed information is available at www.westermo.com/support/product-support.

Agency approvals and standards compliance
Type | Approval / Compliance |
| EMC | EN 61000-6-1, Immunity residential environments |
| EN 61000-6-2, Immunity industrial environments | |
| EN 61000-6-3, Emission residential environments | |
| EN 61000-6-4, Emission industrial environments | |
| EN 50121-4, Railway signaling and telecommunications apparatus | |
| IEC 62236-4, Railway signaling and telecommunications apparatus | |
| DNV Standard for Certification No. 2.4 | |
| Safety | UL/CSA 60950-1, IT equipment |
FCC Part 15.105
Notice:
This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment.
This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instruction manual, may cause harmful interference to radio communications. Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at his own expense.
Type tests and environmental conditions
Electromagnetic Compatibility | |||
| Phenomena | Test | Description | Level |
| ESD | EN 61000-4-2 | Enclosure contact | ± 6 kV |
| Enclosure air | ± 8 kV | ||
| RF field AM modulated | IEC 61000-4-3 | Enclosure | 10 V/m 80% AM (1 kHz), 80 – 800 MHz 20 V/m 80% AM (1 kHz), 800 – 1000 MHz 20 V/m 80% AM (1 kHz), 1400 – 2700 MHz |
| RF field 900 MHz | ENV 50204 | Enclosure | 20 V/m pulse-modulated 200 Hz, 900 ± 5 MHz |
| Fast transient | EN 61000-4-4 | Signal ports | ± 2 kV |
| Power ports | ± 2 kV | ||
| Surge | EN 61000-4-5 | Signal ports unbalanced | ± 2 kV line to earth, ± 2 kV line to line |
| Signal ports balanced | ± 2 kV line to earth, ± 1 kV line to line | ||
| Power ports | ± 2 kV line to earth, ± 2 kV line to line | ||
| RF conducted | EN 61000-4-6 | Signal ports | 10 V 80% AM (1 kHz), 0.15 – 80 MHz |
| Power ports | 10 V 80% AM (1 kHz), 0.15 – 80 MHz | ||
| Pulse Magnetic field | EN 61000-4-9 | Enclosure | 300 A/m, 6.4 / 16 µs pulse |
| Mains freq. 50 Hz | EN 61000-4-16 | Signal ports | 100 V 50 Hz line to earth |
| Mains freq. 50 Hz | SS 436 15 03 | Signal ports | 250 V 50 Hz line to line |
| Radiated emission | CISPR 16-2-3 | Enclosure | EN 61000-6-3 |
| ANSI C63.4 | FCC part 15 | ||
| Conducted emission | CISPR 16-2-1 | AC power ports | EN 61000-6-3 |
| ANSI C63.4 | AC power ports | FCC part 15 | |
| CISPR 16-2-1 | DC power ports | EN 61000-6-4 | |
| Dielectric strength | UL 60950 | Signal port to all other isolated ports | 2 Vrms 50 Hz 1min |
| Power port to other isolated ports | 3 kVrms 50 Hz 1min 2 kVrms 50 Hz 1min (@ rated power < 60V) | ||
| Environmental | |||
| Temperature | EN 60068-2-1 EN 60068-2-2 | Operating | –40 to +70°C |
| Storage & Transport | –40 to +70°C | ||
| Maximum surface temperature | 135ºC (temperature class T4) | ||
| Humidity | EN 60068-2-30 | Operating | 5 to 95% relative humidity |
| Storage & Transport | 5 to 95% relative humidity | ||
| Altitude | Operating | 2 000 m / 70 kPa | |
| Service life | Operating | 10 year | |
| Vibration | IEC 60068-2-6 | Operating | 7.5 mm, 5 – 8 Hz 2 g, 8 – 500 Hz |
| Shock | IEC 60068-2-27 | Operating | 15 g, 11 ms |
| Packaging | |||
| Enclosure, | UL 94 | PC / ABS | Flammability class V-1 |
| Dimension W x H x D | 35 x 121 x 119 mm | ||
| Weight | 0.26 kg | ||
| Degree of protection | IP21 | ||
| Cooling | IEC 529 | Enclosure | Convection |
| Mounting | Horizontal on 35 mm DIN-rail | ||
Functional description

Converter serial interface – optical fiber
ODW-720-F1 is a fiber optic modem that converts between electrical RS-232 and a fibre optic link.
ODW-720-F1 can also be used to convert from RS-232 to RS-485 by using one ODW720-F1 and one ODW-730-F1.
Data rate up to 250 kbit/s
ODW-720-F1 converts data using rates from 300 bit/s up to 250 kbit/s.
Interface specifications
| Power | |
| Rated voltage | 12 to 48 VDC and 24 VAC |
| Operating voltage | 10 to 60 VDC and 20 to 30 VAC |
| Rated current | 300 mA @ 12 V 150 mA @ 24 V 75 mA @ 48 V |
| Rated frequency | DC and 48 to 62 Hz |
| Inrush current I²t | 0.2 A²s |
| Startup current* | 1.0 Apeak |
| Polarity | Reverse polarity protected |
| Redundant power input | Yes |
| Isolation to | RS-232 and Status port |
| Connection | Detachable screw terminal |
| Connector size | 0.75 – 2.5 mm2 (AWG 18 – 13) Connect the unit using at least 18 AWG (0.75 mm2) wiring |
| Shielded cable | Not required |
* External supply current capability for proper startup
| Status | |
| Port type | Signal relay, changeover contacts |
| Rated voltage | Up to 48 VDC |
| Operating voltage | Up to 60 VDC |
| Contact rating | 500 mA @ 48 VDC |
| Contact resistance | < 50 mW |
| Isolation to | RS-232 and Power port |
| Connection | Detachable screw terminal |
| Connector size | 0.2 – 2.5 mm2 (AWG 24 – 13) |
| Shielded cable | Not required |
Branch circuit protection (fuse) is required for this unit with a rating not exceeding 20 A.
The product should be connected to UL Listed power supplies rated 12 – 48 VDC, min 500 mA or 24 VAC, min 500 mA or reliably grounded DC SELV source.
| RS-232 | |
| Electrical specification | EIA RS-232 |
| Data rate | 300 bit/s – 250 kbit/s |
| Protocol | Asynchronous or synchronous |
| Data format | 9 – 12 bits in asynchronous mode Any type in synchronous mode |
| Data retiming | Asynchronous mode only |
| Transmission range | 15 m |
| Isolation to | Status and Power port |
| Connection | 9-pin D-sub female (DCE) |
| Shielded cable | Not required, except when installed in railway applications as signaling and telecommunications apparatus and located close to rails* |
| Conductive housing | Isolated to all other circuits and housings |
* To minimize the risk of interference, a shielded cable is recommended when the cable is located inside the 3 m boundary to the rails and connected to this port.
The cable shield should be properly connected (360°) to an earthing point within 1 m from this port.
This earthing point should have a low impedance connection to the conductive enclosure of the apparatus cabinet, or similar, where the unit is built-in. This conductive enclosure should be connected to the earthing system of an installation and may be directly connected to the protective earth.
Location of Interface ports, LED’s and DIP-switches
ODW-720-F1

* Direction relative to this unit
LED indicators
LED | Status | Description |
| PWR Power | ON | The power is on. |
| OFF | The power is off. | |
| FP | Not used | |
| CH 2 | Not used | |
| CH 1 Channel 1 link status | ON | Fiber link to other units has been established at CH 1. |
| Flashing | Optical power was detected but a link to other units has not been established at CH 1. | |
| OFF | No optical power detected and no link to other units have been established at CH 1. | |
| TD | Flash | Data is received on the electrical interface and transmitted out on the optical interface. |
| OFF | No data was received on the electrical interface. | |
| RD | Flash | Data is received on the optical interface and transmitted out on the electrical interface. |
| OFF | No data was received on the optical interface. | |
| FL R Failure link remote | ON | Remote fiber link failure. A fiber link is out of operation at any other unit than this one*. |
| Flashing | Hardware error or invalid configuration. | |
| FL L Failure link-local | ON | Local fiber link failure. A fiber link is out of operation at this unit. |
| Flashing | Hardware error or invalid configuration. |
* Only valid if used together with ODW-720-F1 units in a multidrop network.
Note: During power-up, all LEDs will turn on for about 1 second.

DIP-switch settings
CAUTION – ELECTROSTATIC DISCHARGE (ESD)
Prevent electrostatic discharge damages to internal electronic parts by discharging your body to a grounding point (e.g. use a wrist strap).

The ODW-720-F1 DIP switches are pre-set from the factory, so that the unit can be used for point-to-point applications, together with an additional ODW- 720-F1, straight out of the box, without the need for any type of user configuration.
The only choice required is if to enable the RTS to CTS signaling function or not.
See the DIP-switch S2:1 description below.
If the ODW-720-F1 is to be used in a multidrop network together with ODW-720-F2 units, please refer to the ODW-720-F2 user guide for details on how to configure the units.

Start-up guide, point-to-point application
Follow the steps below to get the unit up and running in a simple application.

- Using the factory DIP-switch settings:
- Set DIP-switch S2:1 as desired.
- Connect The fiber link between the ODW-720-F1.
- Connect the power supply to both ODW-720-F1.
- After a few seconds, the fiber link should be in operation, indicated by an active CH1 LED.
- Connect the serial cables from PLC master and slave to respective ODW-720-F1.
- Frames from the PLC master that are correctly received the ODW-720-F1 should be indicated by flashing TD LED.
- Frames that are received via the fiber link will be transmitted to the PLC slave and indicated by a flashing RD LED.
- Replies from slave to master will be transferred and indicated in the opposite way.
- The point-to-point application is up and running.
About the interfaces
Power
The power terminal has two independent inputs, +VA and +VB, allowing redundant power input.
The ODW-720-F1 power supply is galvanically isolated from all other interfaces.
Optical fiber interfaces
ODW-720-F1 uses Small Form Factor Pluggable (SFP) transceivers. This means that a wide range of different fiber transceivers and connectors can be used.
RS-232 interface
The RS-232 interface is a female 9-position D-sub. Pin assignments are in compliance with the EIA RS-232 standard.
Status port
The status port connects to an internal relay witch may be used to trigger an external alarm if a fault condition occurs. During normal operation pins 1 and 2 are in contact with each other, and pins 2 and 3 are isolated. During an optical link failure, or power failure, pins 1 and 2 are isolated, and pins 2 and 3 are in contact with each other.
Mounting
This unit should be mounted on 35 mm DIN-rail, which is horizontally mounted inside an apparatus cabinet, or similar.
Snap-on mounting, see figure.
![]() | ![]() |
Cooling
This unit uses convection cooling. To avoid obstructing the airflow around the unit, use the following spacing rules. Minimum spacing 25 mm (1.0 inch) above /below and 10 mm (0.4 inches) left /right the unit. Spacing is recommended for the use of the unit in the full operating temperature range and service life.

Removal
Press down the black support at the top of the unit. See figure.

Westermo • SE-640 40 Stora Sundby, Sweden
Tel +46 16 42 80 00 Fax +46 16 42 80 01
E-mail: [email protected]
www.westermo.com


























