The M203 is a digital input module that will sample and selectively store up to 16 bits of digital data along with a 31-bit time stamp at a rate up to 5 MHz. The 31-bit time tag allows unique time tagging data. The module has the ability to store all data at the specified sample rate or selectively store input values based upon changes in state of one or more of the inputs. This technique provides extensive real-time data compression for certain digital input signals.

The M203 comes along with the M203/AM104 series of signal conditioning modules which has to be purchased separately. The AM104 has 4 options:
+5V Optocoupled Input Accessory Module; 100 Khz max (M203/AM104-1)
+28V Optocoupled Input Accessory Module; 100 Khz max (M203/AM104-2)
Contact Closure Sensing Accessory Module; 100 Khz max (M203/AM104-3)
Programmable Threshhold 0V/25.5V Accessory Module; 5 Mhz max (M203/AM104-4)
Programmable Threshhold -2V/+30V Accessory Module; 5 Mhz max (M203/AM104-5)

You can consult the manual for the specifications of these options.

Applications for the M203:
> Acquisition of transient signals
> Realtime Data Compression
> Logic Analysis
> Event Counting

Features
> Physically implemented on a single wide MA-Module adhering to the ANSI/VITA 12-1996 specification for M-Modules
> The M203 may be installed in any carrier board supporting the M-Module specification