- 2260/2280 sized M.2 Card with B & M keys and latching I/O connectors
- 4 optically-isolated non-polarized inputs
- 4 electromechanical 1A relay outputs
- Change-of-State (COS) detection IRQ generation
- 9” cable (228MM), standard
- Panel-mountable isolation module with 37-pin male D-Sub connector
- RoHS standard
ACCES I/O M.2-IIRO-4 4 Digital Inputs and 4 Relay Outputs with COS M.2 Card


The ACCES I/O M.2-IIRO-4 consists of a 2260/2280 sized M.2 interface card that connects to a Mobile-ITX-sized, DB-37M Isolation Module via an included 9” cable. That module is designed to be easily panel-mounted in any application environment. It uses the high speed PCI Express bus to transfer digital data to and from the card. The digital I/O is compatible with 8255 PPI chips making it easy to program. This allows for simple and trouble-free migration from other ACCES PCI and PCI Express digital I/O cards, but also provides for advanced features enabled by the onboard FPGA logic.
The M.2-IIRO cards are well suited to complex environments, mitigating otherwise challenging ground-loops, high-common-mode, and transient voltage spikes common in electrically-noisy industrial or factory locations. The broad voltage compatibility and high current outputs allows use in a wide range of applications.
The non-polarized inputs support both AC and DC, and configuration jumpers allow 4.7ms input filters to be enabled per-channel, as desired – required for AC use. The isolated inputs support voltages from 3 to 31 VDC/VAC RMS [40Hz to 10000Hz], as well as standard 12/24 AC control transformer signals.
Outputs are 5 Form C (“Single-pole, double-throw”, or SPDT) and 3 Form A (SPST) electromechanical relays capable of 1A continuous-current load.
Change of State (COS) detection and interrupt capabilities are designed to relieve software from polling routines that can consume valuable processing time. Each port can be programmed for detecting state changes on their lines, in which any changes of the enabled port's bits (low-to-high or high-to-low) will generate an IRQ. An ISR (interrupt service routine) then determines which bit changed state and clears the interrupt.
PC Interface | M.2 Card |
Isolated Inputs | 4 |
Type | Non-polarized, optically isolated from each other and from the computer (CMOS compatible) |
Voltage | 3 to 31 DC or AC RMS (40 to 10000Hz) |
Isolation | 500V channel-to-ground and channel-to-channel |
Resistance | 1.8KΩ in series with opto-coupler |
Filter Response | Rise-time: 4.7 ms Fall-time: 4.7 ms |
Non-Filter Response | Rise-time: 10 μs Fall-time: 30 μs |
Relay Outputs | 4 |
Type | 5 Form C (SPDT) and 3 Form A (SPST), Ag with Au clad,single crossbar for M.2-IIRO-8; 4 Form C for M.2-IIRO-4 |
AC Load | 0.5A at 125 VAC (62.5 VA max) |
DC Load | 1A at 24 VDC (30W max) |
Switching Voltage | 125 VAC, 60 VDC, max |
Switching Current | 1A max |
Contact Resistance | 100 mΩ, max |
Contact Life | 5 million operations, min |
Temperature | Operating: 0°C to 70°C (order -T option for industrial temperature -40°C to 85°C) Storage: -65°C to 150°C |
Humidity | 5% to 95%, non-condensing |
Power Required | +3.3VDC @ 730ma (typical) all relays on |