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Products   >   Services   >   End-of-Life Products   >   Opal-MM Opto In & Relay Out Module
8 optoisolated digital inputs
8 SPDT relay (form C) outputs
DC inputs 3 - 24V
AC inputs 3 - 24V, 40Hz or greater
Long lifetime relays (10,000,000 operations)
500VAC or DC isolation between board and signals
-40°C to +85°C operating temperature
Customers who use this product also use:
40-pin I/O Cable

This product can be customized and ruggedized. Click here for more information.
See Opal-MM Opto In & Relay Out Module Technical Resources
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Opal-MM Datasheet
(.pdf, 139.3 kb)
Opal-MM Manual v1.22
(.pdf, 272.4 kb)
Opal-MM Example Programs for UD 5.91
(.zip, 152.7 kb)
Universal Driver Software

Opal-MM Opto In & Relay Out Module

8 Channel Optoisolated Input & 8 Relay Output PC/104 Module

Opal-MM Opto In & Relay Out Module
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AC Input Operation
Signal Isolation
Output Relay
I/O Header
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Opal-MM is a PC/104 format digital I/O module designed for industrial applications requiring isolation between the computer and the external signals it is monitoring and controlling. This module features 8 optoisolated digital inputs and 8 relay outputs. Each input can accept both AC and DC voltages as low as 3V and as high as 24V.

AC Input Filter

An on-board input filter circuit allows the sensing of AC inputs from 40Hz to 100KHz. The presence of an appropriate AC input signal will generate a DC signal at the output that can be read by the computer. This filter circuit is selectable on a channel by channel basis.

Output Relays

The 8 relay outputs are SPDT format (form C). Each relay has 3 contacts: Common, Normally Open, and Normally Closed. For safety and reliability, all relays are at their power-off state at power-up or system reset. Each relay can switch both AC and DC voltages.


All I/O is isolated from the PC up to 500V AC or DC. The relays have long lifetime (10,000,000 operations) and quick actuation time (5ms max operate and release). A single 40-pin I/O header is used for all I/O.

Please note: Individual input and output channels are not isolated from each other at this voltage. The isolation specification applies only between the I/O points as a group and the remainder of the circuitry. AC Input Operation

Opal-MM can monitor AC inputs as well as DC inputs. A low-pass filter is provided for each input line that can be switched on independently for each channel for AC operation. With this filter switched on, a sine wave or square wave signal with 40Hz or higher frequency and 3V to 24V peak-to-peak amplitude will appear as a steady-state DC signal to the board and can be read reliably by the user's program.

Signal Isolation

Opal-MM provides isolation on its input and output lines. The board will withstand up to 500V DC or AC difference in potential between the I/O lines and the rest of the board's circuitry. Note: This isolation specification does not apply between individual input or output channels; it applies only between the I/O lines and the board. In many applications, channel-to-channel isolation is not required; frequently the inputs or outputs all share a common line, requiring only isolation between the I/O lines as a group and the control circuitry. Please verify the configuration and isolation requirements of your application before selecting any isolated I/O board. Each input and output channel on Opal-MM is completely independent and does not share any signal trace with any other channel. Therefore, every channel is isolated from every other channel. However, the trace spacing at the I/O connector does not satisfy requirements for the 500V rating. If high isolation is required between individual channels, do not use this product. See Pearl-MM instead.

I/O Header

OUT 7 C 1 2 OUT 6C
OUT 7 NC 3 4 OUT 6 NC
OUT 7 NO 5 6 OUT 6 NO
OUT 5 C 7 8 OUT 4 C
OUT 5 NC 9 10 OUT 4 NC
OUT 5 NO 11 12 OUT 4 NO
OUT 3 C 13 14 OUT 2 C
OUT 3 NC 15 16 OUT 2 NC
OUT 3 NO 17 18 OUT 2 NO
OUT 1 C 19 20 OUT 0 C
OUT 1 NC 21 22 OUT 0 NC
OUT 1 NO 23 24 OUT 0 NO
IN 7 A 25 26 IN 7 B
IN 6 A 27 28 IN 6 B
IN 5 A 29 30 IN 5 B
IN 4 A 31 32 IN 4 B
IN 3 A 33 34 IN 3 B
IN 2 A 35 36 IN 2 B
IN 1 A 37 38 IN 1 B
IN 0 A 39 40 IN 0 B


Optoisolated Inputs
Inputs 8 nonpolarized optoisolators
Input volt.
DC inputs: 3V min, 24V max, not polarized
AC inputs: 3V p-p min, 24V p-p max, 40Hz or greater
Input switch time 100mx max
Input impedance 1.8KΩ min
AC input filter Selectable on a per-channel basis
Relay Outputs
Outputs 8 relays
Relay type SPDT (Form C)
Max power
DC: 30VDC/1A
AC: 125VAC/0.1A resistive, 125VAC/0.2A inductive
Max switching cap. 30W (DC), 50VA (AC)
Max operating voltage 220DVC, 250VAC
Contact resistance 50mΩ max
Relay lifetime 10,000,000 operations
Actuation time 5ms max, operate or release
I/O header 42 x 20 pin header; on .1" connecters
Mating Cable: DSC #C-40-18
Isolation (all I/O) 500VDC or AC, input to board or board to output
Power supply +5VDC ±10%
Current consumption 200mA typical, all relays off; Additional 40mA per activated relay
Operating temp. -40°C to +85°C
Weight 3.0oz/85g
RoHS Compliant

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Opal-MM Opto In & Relay Out Module
available models:
Opal-MM 8 Optoisolated Inputs, 8 Relay Outputs
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VDC 2006 Platinum Vendor Award