Westermo MD-21 工业转换器使用手册
Str?mslingeomvandlare Current loop converter
Stromschleifenwandler
INSTALLATIONSANVISNING INSTALLATION MANUAL INSTALLATIONS ANLEITUNG
6151-2002
www.westermo.se
?
W e s t e r m o T e l e i n d u s t r i A B ? 1999R E V . A
Isolation Protection CE Approved
Specifications
Transmission Asynchronous, full/half duplex or simplex
Interface 1EIA RS-232-C/CCITT V.24
9-position D-sub female / screw-terminal
Interface 220mA current loop, selectable active or passive
Data rate Up to 19200 bit/s
Indicators Power, RD, TD
Isolation Galvanic isolation with opto-coupler
(data transmission) and transformer (supply)
Isolation voltage1500V
Overvoltage protection Mains:Breakdown voltage 430V at 230V AC
and 220V at 115V AC*
Interface 2:Breakdown voltage transmitter and
receiver 37V. Surge capacity 0.6 kW for 1 ms
Power supply**115V*/230V AC +15/-10% 48-62Hz
Fuse100mA fast 5x20mm
Power consumption Max 4VA at 115V and 230V
Temperature range5-50°C, ambient temperature
Humidity0-95% RH, non-condensing
Dimensions55x100x128 mm
Weight0.4 kg
Mounting On a 35mm DIN-rail
** For other power supply voltages contact Westermo.
* Only MD-21 115V
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Settings MD-21
The MD-21 can through different switch settings be adapted to a variety of running conditions. To set the switches, open the lid on the top of the plastic case.
WARNING! DO NOT OPEN CONNECTED UNIT
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Connections MD-21
Line connection
(5-Position screw-terminal)
MD-2120mA current loop equipment
Trans-mitter
Receiver
1
234
5R+
R-T+
T-T+T-R+R-Receiver Trans-mitter Shield 1)Power connection (AC)(3-position screw-terminal)
Line connection MD-21
I=input O=output. MD-21 is a DCE (Data Communication Equipment). NC=not connected.
1)If shielded cable is used, connect the shield only at one end to avoid ground currents.
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6151-2002Transmission rate bit/s Transmission range (interface 2)
Switch settings
According to MD-21
Connections
According to MD-21, except power supply
MD-21 DC Specifications
Power supply
12-36V DC Power consumption Max 3W Isolation 500V
Fuse F1
1.6A fast 5x20 mm
All other specifications according to MD-21
Cable 42pF/m 6001200240048009600192000.3 mm 2
6000 m
5000 m
4000 m
3000 m
500 m
200 m
1– Voltage 2
+ Voltage
Screw no.Power Supply
Connecting the MD-21 in a 20mA current loop
S3:1, 2 on
S4:1, 2 on
Functional description
When transmitting from the master, RD and TD flash. RD flashes on both slaves. When transmitting from a slave both RD and TD flash and on the other slaves and
the master RD flashes.
S3:1, 2 on
S4:1, 2 on
Functional description
When transmitting from a slave the TD led flashes only on that unit. The RD led flashes only on the master modem.
When transmitting from the master, TD flash. RD flashes on both slaves.
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Hints Array The 20mA current loop interface, or TTY as it is sometimes known, is a
popular industrial communications standard. The system relies on a cur-
rent generator running on both the transmit and receive circuits. On each
circuit it is important to have only one current generator supplying cur-
rent into that circuit. For this reason the MD-21 can have its current gen-
erators set to be either active or passive. It is important to check the state
of all attached equipment to ensure correct setting on the MD-21. A maxi-
mum of 6 devices can be connected in a loop.
The RS-232 interface is configured as DCE (Data Communication
Equipment). Most printers, PC’s and terminals are set as DTE (Data
Terminal Equipment). Some recomendation of cable configurations are
given below.
If any problems do occur on set up of the MD-21, the LED’s will be help-
ful.
- PWR:The unit has power.
- RD:Data received on line interface.
- TD:Data received on RS-232 interface.
A good way to check the MD-21 is to carry out a loop back test. Ensure
that either the transmitter or receiver are set to active, but not both
active or both passive. Connect T+ to R+ and T- to R-. Connect the
RS-232 interface to a terminal. When keys are pressed on the terminal
you should receive the echo on screen. The TD & RD lights will both
flicker simultaneously as you press the keys.
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1) 0 ?resistors R1, R48-R50 are normally not mounted.
2) Metal housing on D-sub is connected to PE if R is mounted.
R = R3 on the DC-mod and R1 on AC-mod.
V.24/RS-232
TD
DSR DCD
CTS
RTS
RD
SG
D-sub housing
PE Power supply
Line
T+T-R+R-Shield
6151-200201.99 T u n a T r y c k A B , E s k i l s t u n a , S w e d e n
Westermo Teleindustri AB ? S-640 40 Stora Sundby, Sweden
Phone +46 16 612 00Fax +46 16 611 80
E-mail: info@westermo.se ? Westermo Web site: www.westermo.se
Westermo Teleindustri AB have distributors in several countries,
contact us for further information.
Westermo Data Communications GmbH Bruchsaler Stra?e 18, 68753 Wagh?usel
Tel.: +49(0)7254-95400-0 ? Fax.:+49(0)7254-95400-9E-Mail: westermo.germany@t-online.de
Westermo Data Communications Ltd
Solent Business Centre ? Millbrook Road West Millbrook, Southampton ? SO15 0HW
Phone: +44(0)1703-704 611 ? Fax.:+44(0)1703 702 682E-Mail: sales@https://www.wendangku.net/doc/0e18996802.html,
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