westermo MDW-45 Serial Converter User Guide

: June 9, 2024
: westermo

Table of Contents

General information
Safety and Regulations
Care recommendations
Type tests and environmental conditions
Functional description
Interface specifications
LED Indicators
References
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westermo MDW 45 Serial Converter-

MDW-45
Converter
RS-232 – RS-422/485

General information

Legal information
The contents of this document are provided “as is”. Except as required by applicable law, no warranties of any kind, either express or implied, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose, are made in relation to the accuracy and reliability or contents of this document. 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
---|---|---|---
WARNING| Indicates a potentially hazardous situation| Possible death or major injury| Major damage to the product
CAUTION
| Indicates a potentially hazardous situation| Minor or moderate injury| Moderate damage to the product
NOTICE
| Provides information in order to avoid misuse of the product, confusion or misunderstanding| No personal injury| Minor damage to the product
NOTE
| 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 in to an apparatus cabinet or similar, where access isrestricted 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
The power supply wiring must be sufficiently fused.
It must be possible to disconnect manually from the power supply.
Ensure compliance to national installation regulations.
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).

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.

Care recommendations

Follow the care recommendations below to maintain full operation of 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.

Declaration of Conformity
Hereby, Westermo declares that this product is in compliance with applicable EU directives and UK legislations. 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 61000-6-2
EN 61000-6-4	Emission industrial environments

FCC Part 15.105 Notice:

This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:

Reorient or relocate the receiving antenna.
Increase the separation between the equipment and receiver.
Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.
Consult the dealer or an experienced radio/TV technician for help.

Type tests and environmental conditions

Electromagnetic Compatibility

20 V/m 80% AM (1 kHz), 800 – 960 MHz

20 V/m 80% AM (1 kHz), 1 400 – 2 700 MHz

2 kVrms 50 Hz 1min (@ rated power < 60V)

Functional description

The MDW-45 is an RS-422/485 to RS-232 converter. This device can be used in multidrop and point to point applications to connect devices like PCs, PLCs, drives and other automation equipment. In 2-wire half duplex applications (RS-485) the MDW-45 can automatically control the state of the data bus based just on the data it receives. This allows the unit to be used with equipment that has no handshaking signal. The maximum transmission rate possible is 115.2 kbit/s.

westermo MDW 45 Serial Converter-fig1

Interface specifications

Power

| MDW-45 LV| MDW-45 HV
Rated voltage| 12 to 48 VDC| 95 to 240 VAC

110 to 250 VDC

Operating voltage| 9.6 to 57.6 VDC| 85.5 to 264 VAC 88 to 300 VDC
Rated current| 95 mA @ 12 VDC

35 mA @ 48 VDC

| 21 mA @ 95 VAC

10 mA @ 110 VDC

Rated frequency| DC| 48 – 62 Hz / DC
Polarity| Reverse polarity protected| Polarity independent
Connection| Detachable screw terminal| Detachable screw terminal
Connector size| 0.2 – 2.5 mm² (AWG 24-12)| 0.2 – 2.5 mm² (AWG 24-12)
RS-422/485

≤ 1200 m, depending on data rate and cable type

Settings| 120 Ω termination and failsafe biasing 680 Ω , by DIP-switch
Protection| Installation Fault Tolerant (up to ±60 V)
RS-232

Locations of Interface ports, LED`s and DIP-switches

westermo MDW 45 Serial Converter-fig2

Railway installation close to the rails (RS-232, RS-422/485)

For a cable located inside 3 m boundary and connected to this port, the use of shielded cable is recommended, this to minimize the risk of interference. 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.

LED Indicators

LED| Status| Description|

---|---|---|---
PWR| ON| In service
OFF| Out of service
TD| ON| Transmitted Data: Displays data received from the local RS-232 port
OFF| No data
RD| ON| Received Data: Displays data leaving the modem on the RS-232 port
OFF| No data
RTS| ON| Status of RTS from the RS-232 interface
OFF| No RTS
CTS| ON| Status of CTS from the RS-232 interface
OFF| No CTS

DIP-switch settings
Before DIP-switch settings:
Prevent damage to internal electronics from electrostatic discharges (ESD) by discharging your body to a grounding point (e.g. use of wrist strap).

westermo MDW 45 Serial Converter-fig4

S2 Below panel, RS-422/485 termination

No termination and fail-safe
Termination with fail-safe (2-wire)
Termination with fail-safe (4-wire)

Note! DIP-switch alterations are only effective after a power on.
Factory settings
Data rate – 9600 bit/s, data format – 10 bitBus format, 2-wire
Note: Switch 1:8 is not used
No termination and fail-safe
Unit specific description
When the converter is set to data-control mode the transmitter is activated by data on TD (RS-232).The time the transmitter stays active corresponds to one character-time plus the turning time for the set data rate and number of bits. If more data arrives on TD before the turning time has expired the transmitter stays active for an additional one character time and so on. In RTS-control mode the transmitter is activated by the RS-232 RTS-signal. In this mode the dip-switches for data rate and number of bits have no effect. The LED indicators show the status of the data signals. The fail-safe termination ensures that the signal level at the receiver is in ‘mark state’ (differential>0.2 Volts) when there is no data on the RS-485 bus. Full duplex is only possible if 4-wires are used.
Field of application
RS-422 and RS-485 were both designed for multidrop applications. When a system is installed it should always form a bus structure (see diagrams). Star shaped networks should never be created; there are other Westermo products that can be used to create star net applications. To install a system according to the RS-422/485 specification it is
very important that the line is terminated at the correct points. The recommendation is to terminate the receiver on the master unit and the final bus slave unit. See diagrams for details of how this is done with RS-485 (2-wire) and RS-422 (4-wire).

westermo MDW 45 Serial Converter-fig6