MLT-FR | 4-20 mA & Serial Data Output | Stopwatch Timing for Single Events | DIN Rail Transmitter

The Micron Meters stopwatch transmitter puts out isolated analog and serial data output signals whose values track the time of single events which produce start and stop pulses, or the accu­mulated time of multiple events. It can also time the width of a single pulse. The highest resolution is 0.2 µs, making the transmitter ideal for fast events. The longest timing interval is 999,999 hrs. For long events, the analog output is updated continuously during timing. There are two primary timing modes:

• A-A Stopwatch Mode. Time is measured between a start pulse and a stop pulse, both on Channel A, from either the positive or negative edges.
• A-B Stopwatch Mode. Time is measured between a start pulse on Channel A (positive or negative edge) and a stop pulse on Channel B (positive or negative edge). This mode allows inputs from different sources. In addition, the A and B inputs can be tied together to start the stopwatch with one polarity and stop it with the other polarity.

Event time (Item #1) is measured by counting 5.5 MHz clock pulses from a calibrated quartz crystal. The stopwatch output is updated during timing at a rate controlled by a gate time, up to 25/sec. Time is reset to zero when the next start pulse occurs. Accumulated time from multiple events up to 999,999 hours (Item #2) is also tracked.

The dual-channel signal conditioner used for pulse detection accepts inputs from proximity switches with PNP or NPN output, TTL or CMOS logic, magnetic pickups, contact closures, and other signals from 12 mV to 250 Vac. Jumper selections provide optimum operation for different sensor types and noise conditions. A built-in 5V, 10V or 24V dc excitation supply can power proximity switches and other sensors, and eliminate the need for an external power supply.