westermo MD-45 HV Converter Instruction Manual
- June 16, 2024
- westermo
Table of Contents
MD-45 AC
MD-45 L V/HV
INSTALLATION MANUAL
6157-2213
©Westermo T eleindustri AB • 2003 • REV .A
Converter RS-232 – RS-422/485
Intruduction
The MD-45 is used to convert between RS-422/485 and RS-232/V.24 signals.This
device is often used in multidrop applications connected to a PC or PLC.
In 2-wire half duplex applications (RS-485) the direction of the bus can be
controlled by data which means that the converter turns the bus depending on
the data sent on the bus. This makes it possible to use the unit with
equipment that has no handshaking signals.The maximum transmission rate
possible is 115.2 kbit/s.
Safety
General:
Before using this unit, read this manual completely and gather all information
on the unit. Make sure that you understand it fully. Check that your
application does not exceed the safe operating specifications for this unit.
Before installation, maintenance or modification work:
Prevent damage to internal electronics from electrostatic discharges (ESD) by
discharging your body to a grounding point (e.g. use of wrist strap).
Prevent access to hazardous voltages by disconnecting the unit from AC/DC
mains supply and all other electrical connections.
Installation:
This unit should only be installed by qualified personnel.
This unit should only be installed in a “restricted access area”, for example
a lockable cabinet where access is restricted to service personnel only.
This unit is intended for permanent connection to the AC/DC mains supply.
The power supply wiring must be sufficiently fused, and if necessary it must
be possible to disconnect manually from the AC/DC mains supply. Ensure
compliance to national installation regulations.
Unit with the rated voltage exceeding 42.4 V peak or 60 VDC, is defined as
class I equipment with a protective earthing conductor terminal.
Unit with the rated voltage up to 42.4 V peak or 60 VDC, is defined as class
III equipment and shall be separated from hazardous voltage by double or
reinforced insulation.
This unit uses convection cooling.To avoid obstructing the air flow around the
unit, follow the spacing recommendations (see under chapter Installation).
Approvals
Conformity with the Directive 73/23/EEC (Low Voltage Directive) has been
assessed by application of the standard EN 60 950.
Conformity with the Directive 89/339/EEC (Electromagnetic compatibility) has
been assessed by application of standards EN 61000-6-2 (industrial immunity)
and EN 61000-6-3 (residential emission).
3.1 Declaration of conformity
Westermo Teleindustri AB
Declaration of conformity
The Westermo Teleindustri AB company declares that the listed products conforms to the Council Directive 89/336/EEC, related to Electro Magnetic Compability and 72/23/EEC Low Voltage Directive.
Type of equipment: Model:| DIN-rail converter RS232-RS422/485
MD-45 AC
MD-45 HV
MD-45 LV| 3157-0101, 3157-0110
3157-1101
3157-0001
---|---|---
Standards:
EMC: EN 61000-6-3/CISPR22(EN 55022): Class B
EN 61000-6-2/EN 61000-4-2
EN 61000-6-2/EN 61000-4-3
EN 61000-6-2/EN 61000-4-4
EN 61000-6-2/EN 61000-4-5
EN 61000-6-2/EN 61000-4-6
EN 61000-6-2/EN 61000-4-11
EN 61000-6-2/EN 61000-4-16
Safety: EN 60950
Reference: Installation manual MD-45 AC/HV,LV Art. Nr. 6157-2003
Hans Levin
Technical Manager
May 2003
Specifications
4.1 Interfaces
Power
| Model description | MD-45 AC | MD-45 LV | MD-45 HV |
|---|---|---|---|
| Rated voltage | 230 VAC | 12–30 VAC | |
| 12–48 VDC | 95–240 VAC |
110–250 VDC
Operating voltage| 207–253 VAC| 10–45 VAC
9,6–60 VDC| 85.5–264 VAC
88–300 VDC
Rated currant| 22 mA| 300 mA| 25 mA @ 240 V,
50 mA @ 95 V
Rated frequency| 48–62 Hz| 48–62 Hz| 48–62 Hz
Polarity| PE, L and N| Independent| PE, L and N
Connection| 3-pos screw block| 2-pos screw block| 3-pos screw block
Connector size| 0.2 – 2.5 mm2 (AWG 24-12)
Fuse| To be externally fused
RS-485/422
| Electrical specification | RS-422/485 |
|---|---|
| Data rate | 1 200 – 115 200 bit/s |
| Connection | 5-pos screw block |
| Connector size | 0.2 – 2.5 mm² (AWG 24-12) |
| Circuit type | TNV-1 |
RS-232
| Electrical specification | RS-232-C |
|---|---|
| Data rate | 1 200 – 115 200 bit/s |
| Connection | 9-pos D-sub, DCE |
| Circuit type | SELV |
4.2 Insulation between interfaces
| Power (MD-45 HV and AC) to all other | 3.0 kV RMS @ 50 Hz and 60 s duration |
|---|---|
| Power (MD-45 LV) to all other | 1.0 kV RMS @ 50 Hz and 60 s duration |
| RS-232 to RS-485/422 | 1.0 kV RMS @ 50 Hz and 60 s duration |
4.3 Climatic environment
| Temperature, operating | 5 to 55ºC |
|---|---|
| Temperature, storage and transportation | –25 to 70ºC |
| Relative humidity, operating | 5 to 95% (non-condensing) |
| Relative humidity, storage and transportation | 5 to 95% (condensation allowed |
outside packaging)
4.4 Mechanics
| Dimension (W x H x D) | 55 x 100 x 128 mm |
|---|---|
| Weight | 0.5 kg AC, 0.25 kg HV and LV |
| Mounting | 35 mm DIN-rail |
| Degree of protection | IP 20 (IEC 529) |
Maintenance
No maintenance is required, as long as the unit is used as intended within the specified conditions.
Installation
6.1 Mounting /Removal
Before mounting or removing the unit:
Prevent damage to internal electronics from electrostatic discharges (ESD) by
discharging your body to a grounding point (e.g. use of wrist strap).
Prevent access to hazardous voltages by disconnecting the unit from AC/DC
mains supply and all other electrical connections.
Mounting
This unit should be mounted on 35 mm DIN-rail which is horizontally mounted on
a wall or cabinet backplate.
This unit uses convection cooling. To avoid obstructing the air flow 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.
Snap on mounting, see figure.
Removal
Press down the black support at the back of the unit using a screwdriver, see
figure.
6.2 Connections
6.2.1 LED indicators
| PWR | Power Indication |
|---|---|
| RTS | Request To Send modem signal |
| TD | Transmitted Data: Displays data received from the local |
RS-232/422/485 port
RD| Received Data: Displays data leaving the modem on the RS-232/422/485
port
CTS| Clear To Send modem signal
6.2.2 Power (MD-45 HV,AC)
| 3-pos screw terminal | Description |
|---|---|
| L | Line |
| N | Neutral |
| Protective earth |
6.2.3 Power (MD-45 LV)
| 2-position screw terminal | Description |
|---|---|
| No. 1 | –Voltage |
| No. 2 | +Voltage |
6.2.4 Line connection (RS-422/485)
| 5-position screw terminal | Direction | Description |
|---|---|---|
| No. 1 | In | A’ (R+) |
| No. 2 | In | B’ (R–) |
| No. 3 | In/Out | A (T+) |
| No. 4 | In/Out | B (T–) |
| No. 5 | – | Shield |
6.2.5 Terminal connection (RS-232, DCE)
| Screw terminal | 9-pos D-sub | Direction | Description |
|---|---|---|---|
| 7 | 2 | Out | Receive Data (RD) |
| 8 | 3 | In | Transmit Data (TD) |
| 1 & 9 | 5 | – | Signal ground (SG) |
| 2 | 6 | Out | Data set ready (DSR) |
| 6 | 7 | In | Request to send (RTS) |
| 5 | 8 | Out | Clear to send (CTS) |
Screw terminal 3 and 4 not used
6.3 Configuration
6.3.1 DIP-switch settings
DIP-switches are accessible under the lid on top of the unit. DIP-switches are
used to configure the modem.
Warning!
Prevent damage to internal electronics from electrostatic discharges (ESD) by
discharging your body to a grounding point (e.g. use of wrist strap), before
the lid on top of the modem is removed.
Warning! Do not open connected equipment.
Prevent access to hazardous voltages by disconnecting the unit from AC/DC
mains supply and all other electrical connections.
NOTE! The change of DIP-switch settings are valid only after a power on.
If configured by any other method during normal operation, this new
configuration override the DIP-switch settings. However, after a new power on
the DIP-switch settings have precedence.
Functional 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 and turning time for the set data rate and number of bits. If
there is more data on TD before the turning time is ended the transmitter
stays active for additional one character. In RTS-control mode the transmitter
is activated by the RTS-signal. In this mode the switches for data rate and
number of bits has no effect.The LED indicators is controlled by the data
signals.The active termination secures that the signal level at the receiver
is in off-state (>0.2 Volts) when there is no data transmission. Full duplex
is only possible if RS-422 is used.
7.1 Block diagram
7.2 Line connection
*) If shielded cable is used, connect the shield only at one end to avoid ground currents.
7.3 Hints
RS-422/485 was designed for multidrop applications. When a system is installed
it should form a bus structure (see diagrams). Star shaped networks should
never be created, there are other Westermo products designed to work in star
net applications. To get a
correct installation according to the RS-422/485 specification it´s 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). The line transmitter used in the MD-45 is
activated by data received on the RS-232 interface, unlike conventional
converters that rely on a control signal (e.g. RTS). If any problems do occur
on set up of the MD-45, the LED’s will be helpful.
| • PWR: | The unit has power. |
|---|---|
| • RD: | Data received on the RS-422/485 interface. |
| • CTS: | Follows RTS. |
| • RTS: | Status of RTS from the RS-232 interface. |
| • TD: | Data received on RS-232 interface. |
N.B. R+/R–, T+/T– definitions are not standard, it can help to shift A and B if the unit does not work.
OWN COMMENTS
Application examples
Westermo Web site: www.westermo.us
Westermo US
Phone 877-268-3700 Fax
877-268-9700
Web site: www.westermo.us
6157-221303.06 Mälartryck AB, Eskilstuna, Sweden
References
Read User Manual Online (PDF format)
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