Isolated RS485 To RS422 Converter - RS485/RS422 Repeater
Model REP-485/422-9E
Category: RS232 / RS485 / RS422 Repeaters
- General Info
- Specifications
- Pinouts
- Images
- Troubleshooting
- Applications
DESCRIPTION
The REP-485/422-9E is an industrial grade bi-directional externally powered 2.5K isolated RS485 to RS422 converter or RS422 to RS485 converter. This converter will also repeat RS485 or RS422 with opto-isolation. A built-in data direction auto-turnaround feature automatically enables the RS485/RS422 driver when data is present eliminating the need for software drivers, and making the device fully plug-and-play. The REP-485/422-9E is an effective solution for protecting RS485 and RS422 devices from voltage surges, lightning strikes, ground loop conditions and signal noise problems. The unit is not reliant on port power so you do not have to worry about the RS485 or RS422's ability to power the converter. The REP-485/422-9E has a DB9 female connector or terminal block on one RS485/RS422 port, and either a DB9 male connector on the other RS485/RS422 port. Two terminal blocks are included with the package. The terminal block plugs into the RS485/RS422 port, providing screw-lug wire terminations for the port. The unit is enclosed in a aluminum housing. This converter operates from 0 to 115,200 baud.
FEATURES
- Plug-and-Play (Device is Hot-pluggable)
- No Drivers Needed
- Isolated 2.5KV RS-485/RS-422 Converter
- Isolated 2.4KV RS-485/RS-422 Repeater
- External UL Listed 9V or 12V to 100V-240V Power Supply is Provided With Package
- Built-in 600W Surge and 15KV Static Protection
- MTBF(Mean Time Before Failure): 306,000 Hours
- 5 Year Manufacturer's Warranty
- RoHS 3, CE, FCC and REACH Certified
PRODUCT COMPLIANCES

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5 Year Replacement Warranty!
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ISO 9001:2015 QUALITY MANAGEMENT

Our internationally recognized ISO 9001:2015 Quality Management System (Cert. No. 743003912) with a scope of Design, Sales, Distribution of Data Communication and IT Support Services was recognized and certified by TÜV Rheinland of North America known for its very demanding and stringent requirements. For more details see our Quality Policy.
COMMUNICATION | |
STANDARDS: | 2-wire RS-485 and 4-wire RS-422 Standards |
BAUD RATES: | From 300 baud To 115,200 baud |
CONNECTOR TYPES: | RS-485/RS-422 Side: either DB9 Male. RJ45 or 5-way Terminal Block; RS-485/RS-422 Side: either DB9 Male. RJ45 or 5-way Terminal Block; |
DISTANCE: | RS-485/RS-422 Side: up to 4000 ft (1.2km) |
MAX # OF CONNECTIONS: | 128 Connection Drops |
ELECTRICAL | |
DC/AC POWER ADAPTER: | 9-12VDC/1A (Input: 100-240VAC 50/60hz US Type A Plug) |
OPTICAL ISOLATION: | 2500V (2500Vrms 1 min, AC) |
CURRENT CONSUMPTION: | Less Than 100 mA |
STATIC PROTECTION: | 15KV Electric Static Discharge (ESD) Protection |
SURGE PROTECTION: | 600W Surge Protection |
MECHANICAL | |
HOUSING: | Aluminum Case |
WEIGHT: | 3.6oz (100 grams) |
DIMENSIONS: | 4.97 X 2.12 X 0.99 in (126.4 X 54.6 X 25.0 mm) |
ENVIRONMENTAL | |
OPERATING TEMP.: | -40ºF to 185ºF (-40ºC to 85ºC) |
STORAGE TEMP.: | -40ºF to 185ºF (-40ºC to 85ºC) |
OPERATING HUMIDITY: | 5% To 95% - No Condensation |
QUALITY | |
PRODUCT SAFETY: | CE, FCC and RoHS Conformance Certified |
QUALITY MANAGEMENT: | Manufactured and Distributed to ISO 9001:2015 QMS |
MEAN TIME BEFORE FAILURE: | 306,000 Hours |
RELIABILITY: | Low Failure Rate - 99+% Reliability Since Inception |
WARRANTY: | 5 Year Replacement Warranty |
RS485/RS422 Side DB9 Male Or Terminal Block
Signal | T/R+ | T/R- | RX+ | RX- | GND |
Pin # | 1 | 2 | 3 | 4 | 5 |
RS485 | D+ | D- | GND | ||
RS422 | TX+ | TX- | RX+ | RX- | GND |


RS485/RS422 Side DB9 Male Or Terminal Block
Signal | T/R+ | T/R- | RX+ | RX- | GND |
Pin # | 1 | 2 | 3 | 4 | 5 |
RS485 | D+ | D- | GND | ||
RS422 | TX+ | TX- | RX+ | RX- | GND |








Using one REP-485/422-9E unit:
- Check that all connections comply with the connection diagrams.
- Perform a continuity test on one unit:
-
- Connect the REP-485/422-9E in between RS-485/RS-422 path.
- If there is continuity in the data stream then it is working. If the REP-485/422-9E is not being powered properly it will not work at all.
Download FREE FULL VERSION AccessPort Advanced Serial Monitor, Simulation and Data Analysis Software Tool. This software tool is great for testing converters. Supports Windows 98/XP/VISTA/WIN 7/WIN 8/WIN 10. DOWNLOAD SOFTWARE AND USER MANUAL
Below are some of the Industrial, Opto-Isolated, Externally Powered RS485/RS422 converter/repeater applications.
2 Wire RS485 to 4 Wire RS422 Mode Option

FIGURE 1: CONVERTING FROM RS485 TO RS422 MODE

FIGURE 2: RS485 TO MASTER / SLAVE MULTI-DROP CONFIGURATION IN RS422 MODE
4 Wire RS422 To RS485 Mode Option

FIGURE 3: CONVERTING FROM RS422 TO RS485 MODE

FIGURE 4: RS422 TO MASTER / SLAVE MULTI-DROP CONFIGURATION IN RS485 MODE
Repeat RS485 or RS422 Mode Option

FIGURE 5: REPEATING RS485 WITH ISOLATION MODE
