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DIACR44: Fast Async RS485/RS422 to RS485/RS422 Dual Isolated Automatic Converter/Repeater


DIACR44 with Box

DIACR44 Label

"Let me spin a very large
RS485 network for you!"

  • Fast RS485/RS422 to RS485/RS422 auto TX-enable (or fixed enable) interface converter for 4-wire and/or 2-wire, communications, in point-to-point or multi-drop communications networks, at distances up to 4000 ft. and data rates up to 115.2Kbps.

  • The unit can be used as a 4-wire to 4-wire repeater, a 2-wire to 2-wire repeater, or as a converting 2-wire to 4-wire repeater.

  • Galvanic (Opto/Xformer) Isolation helps eliminate noise, and protects equipment form destructive transients found in industrial applications.

  • This unit is very flexible and can be used as a versatile "building block" to extend both the distance and/or the number of RS485/RS422 units on a network.

General Description:

The DIACR44 is a very flexible converter/repeater that can be used in 2-wire and/or 4-wire applications. The unit features Dual Isolation (transformer and optical), a wide power supply range (9 to 35VDC), edge mounted LED indicators, removable screw terminal strips, on-board transient protection, jumper selection for bias, termination, and operating modes. The DIACR44 can be configured to solve many communications problems both as a repeater and as a converter.

The DIACR44 is designed as a robust converter/repeater for industrial applications and other applications (both indoor and outdoor) where galvanic isolation is important. This unit provides superior characteristics/features to solve a wide variety of communications problems. Can be used for point to point, or 4-wire RS422 (or RS485) to multi-drop 2-wire systems.

Need something special? Please contact us. We have additional isolated and non-isolated converters, repeaters, and repeater hubs. Units are generally stock to 2-3 business days for shipment. We design and manufacturer our entire product line, and offer technical support for our units, and can offer system recommendations for your application. Please give us a call: 513-874-4796

Related Files:

pdf icon DIACR44RevD.pdf Unit schematic Rev. D (3.0kV)
pdf icon DIACR44revD-WD.pdf Wiring diagram Rev. D (3.0kV)

Physical Properties and Features:

RS422: 6-wire removable screw terminal interface (RX/TX+, RX/TX-, TX+, TX-, and 2-Commons)
RS485: 3-wire removable screw terminal interface (RX/TX+, RX/TX-, Common)
Power: Removable 2-wire screw terminal interface with full wave bridge input, for 9-35VDC (12-24VAC) operation, typical power is under 1.0 Watt
LEDs: Power(YEL), TX-A(RED), RX-A(GRN), TX-B(RED), and RX-B(GRN)
RS422 Bias: 620 Ohm pull-up and pull-down (on TX only, jumper selectable)
RS485 Bias: 620 Ohm pull-up and pull-down (jumper selectable)
Termination: 120 Ohm (jumper selectable in 4 places)
Special: Jumper selection for flexible operating modes, LED indicators
Protection: P6KE6.8A Transient Voltage Suppressors inside 1N4004 diode bridge on data lines


Distance: RS422/RS485 up to 4000 ft. (1250 meters) on each side of the interface
Operation: 4-wire full-duplex (RS422/RS485) to 2-wire half-duplex RS485 factory default setting (also used as 2/4-wire to 2/4-wire repeater).
Format: Asynchronous data with any combination of bits, parity, stop
Speed: Up to 115.2Kbps+ (MAX489 slew rate limited drivers)
Temperarure:   0-65C (32-150F) ambient
Humidity: 10-90% non-condensing
Voltage: 9-35VDC, (12-24VAC)
Power: Under 1.0 Watt (typical) + external load
Size: 4.50" X 3.50" X 0.9" (PC Board), with connectors: 5.00" X 4.00"
Mounting: 4-Places 4.00" X 3.00" (built-in standoffs for #6 hardware)

Options and Ordering Information:

DIACR44: $189.00 ea. (Circuit board only)
Enclosure: $10.00 ea. (Large)
Cable: None - screw terminal connections only
Supply: $8.50 ea. (12VDC @ 200/300 mA wall power supply).

*DIACR44 with all options: DIACR44-BPS @ $207.50 ea. (Qty. 1-9)

Need a different configuration or more information? Give Ron a Call at 513-874-4796 or 513-638-0228(Cell)

Webstore: DIACR44

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