Analog and Digital I/O

Model 626

Model 426

Six versatile 24-bit counters for encoders, interrupt  generation

Battery backup of counters

Four 13-bit D/A outputs

Sixteen 14-bit differential A/D inputs, 20 kHz rate

Watchdog timer may be used to reset PCI bus

48 bi-directional digital signals for solid state relay
boards, 20 with edge detection & interrupts


The Sensoray Model 626 low cost interface saves space in PCI bus systems by combining five functions into a half-size module. Five flat cables connect the Model 626 to external breakout boards.

Encoders and Counters
Three 24-bit up/down counter pairs may be configured for six incremental encoders each having 24-bits of resolution. Each channel accepts two phased TTL or RS-422 signals plus an index signal to track encoder direction and displacement. Each input is conditioned and synchronized to the 626’s internal clock.

Unlike conventional counters, the 626’s counters do not accumulate errors when the encoder dithers or changes direction. The 626 supplies 5 volt power to each encoder channel. All counters are programmable and may optionally generate interrupts.

The counter channels have a battery backup feature that keeps them running during a power failure. The 626’s battery charger will recharge an external 3.6V NiCd when power is restored.

Each counter may be programmed to function as a timer using the 626’s internal clock or an external clock. When paired,  48-bit counters may be used for frequency measurement.

Sixteen differential input channels are multiplexed to a sample/hold and successive approximation A/D. Each channel may be programmed for
5V or   10V. No trim adjustments are needed.


Four voltage outputs may be programmed for
10 volts. A unique circuit prevents unpredictable D/A outputs during CPU initialization. All outputs are reset to zero volts whenever a bus reset occurs.

The 626’s watchdog timer may be connected to the bus reset via a 2-pin connector. It may be enabled or disabled under program control. The timer is automatically disabled whenever a bus reset occurs.

Digital I/O
The model 626’s forty-eight digital lines have standard pin outs for solid-state relay boards. Each line is soft- ware programmable as an input or output. Forty inputs may be programmed for edge detection and interrupts. The status of output lines may be monitored by software. Whenever a system reset occurs all output channels are turned off.

All the features of model 626 may be exercised using software development kit, SDK626.  This 32-bit DLL for Windows 95/98 and NT allows the use of multiple 626 boards.



Operating temperature 0 C to 70C
PC bus interface PCI, 32-bit, 33 MHz
Input power < 3 watts
A/D Converter
Number of channels 16 differential
Input resistance 100 MW
CMRR 100 dB minimum
Max. common mode
5 volts
Resolution 14-bits
Input ranges 10, 5 V
Offset error   1/2 LSB
D/A converter
Conversion time 50 mS
Resolution 13-bits
Offset error 2 bits
Output voltage 10 volts
Output resistance 87 W
Digital I/O
Number of channels 48 bi-directional
Output voltage 0 to 5 V open collector
Output sink current 100 mA @1.1 V
Encoder I/O
Number of channels 6 quadrature, 24-bit
Input voltage TTL or RS-422
Input frequency 2 MHz w/internall clock
1 MHz w/external clock
Quadrature multiplier x1, x2, x4
Watchdog Timer
Time-out 1/8, 1/4, 1, 10 sec

2-pin connector may be connected to the bus reset line to allow a system reset from software


Ordering Information

Analog I/O Accessory
Screw terminal board
Terminal board with DIN rails
18” analog cable, 50-pin 7501C
1 meter analog cable, 50-pin 7501C1
Digital I/O Accessory
18” digital cable, 50-pin 7501C
1 meter digital cable, 50-pin 7501C1
24 position relay board 720RB
24 position relay board with DIN mounting hardware 720RB-
Encoder Accessory
18” encoder cable, 26-pin 7503C3
1 meter encoder cable, 26-pin 7503C4
Encoder terminal board with DIN snap rails 7503T-
NiCd battery, 3.6V