RS232C < - > RS485 CONVERTER’S MANUAL
Model: LD15U
www.interfaceproducts.info
Phone: 91-79-4002 4896 / 97 / 98 (M) 0-98253-50221
INTRODUCTION
Milestone’s model LD-15U is a RS232 to RS 485 converter is designed for highspeed data transmission between computer system and or peripherals over long
distance under high noise conditions. They provides dual line interface per signal.
APPLICATIONS
Application for these converters can be for factory automation, programmable logic
controllers, attendance recording systems, Barcode Readers, remote data
transmission, remote terminals, EPABX etc.
Technical Specifications
Input (RS232C)
Output (RS485)
Signal Protection
Selection Switch – 1
Selection Switch – 2
Maximum Distance
Output Cable
Transient Protection
Indication
Power Supply
Size
RS232C - TxD, RxD, DSR (for control), GND
RS485 – Tx+, Tx-, Rx+, Rx-
Each signal is protected by spike suppressor,
Opto-Isolation
Fuse protection
Rear side has 2 way Select switch for
Selecting 2 wire or 4 wire mode in RS422 / RS485.
1. Rear side has 3 way Select switch for selecting AUTO
Mode (no Handshaking Signal),
2. DSR+ Mode (+12V Control) for controlling data flow
3. DSR– Mode ( -12V Control) for controlling data flow
1.2 Kms. @ 19,200 bps
Shielded twisted pair cable –90 Ohms/km. (Not supplied)
2500 V Peak
Power LED Rx LED Tx LED DSR
230 V, 50 Hz
117 mm x 105 mm x 55mm
www.interfaceproducts.info
Phone: 91-79-4002 4896 / 97 / 98 (M) 0-98253-50221
INSTALLATION INSTRUCTIONS
Switch Settings
1. 2-WAY SELECT SWITCH:
Select 2-wire (half duplex) or 4-wire (full duplex) mode on 2-way switch on the
back panel.
2. 3-WAY CONTROL SWITCH: (Optional / Old Models) (In new models, it is fully automatic. No selection required)
A. Position 1 - Auto - No Handshake Control
B. Position 2 - DSR + (+12V) to enables RS485 output
C. Position 3 - DSR - (–12V) to enables RS485 output
TABLE I: RS 232 Port – D9 Female Connector
Pin No.
Signal Name Input / Output
2
3
4
5
6,8
Tx Output
Rx Input
DSR Input
Signal Ground -
DTR, DTS Output
TABLE II: Output port-D9 Male connector
Pin No.
3 -Rx
4 +Rx
5 +Tx +Tx/+Rx
6 -Tx -Tx/-Rx
7 GND. GND.
1 Frame Ground Frame Ground
Signal Name Input / Output
www.interfaceproducts.info
Phone: 91-79-4002 4896 / 97 / 98 (M) 0-98253-50221
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