The 7421 is a Legacy product and is not recommended for new designs. The lead time for the 7421 may be as long as 12 weeks and may require a minimum quantity order. Please call for availability.

Description
The Sensoray Model 7421 low cost interface saves space in STD bus systems by combining five functions into one module. Four flat cables connect the Model 7421 to external breakout boards.

Encoders
Three 16-bit up/down counter channels are optimized for incremental encoders. Each channel accepts two phased TTL or RS-422 signals to track encoder direction and displacement. Unlike conventional counters, the 7421 counters do not accumulate errors when the encoder dithers or changes direction. The 7421 supplies 5-volt power to each encoder channel.

A/D
Eight differential input channels are multiplexed to a sample/hold and successive approximation A/D. A resistor-programmable instrumentation amplifier allows gains of 1 to 1000. The 15-volt outputs from the DC/DC supply ensure A/D linearity for 10 volt input signals.

D/A
Four voltage output channels may be programmed for 0 to +10 volts. One channel has a remote sense input to minimize line loss errors. All output voltages are reset to zero volts whenever a bus reset occurs.

Watchdog Timer
The 7421's watchdog timer output may be routed to either bus reset or nonmaskable interrupt. It may be enabled or disabled under program control. The timer is automatically disabled whenever a bus reset occurs

Digital I/O
The Model 7421 has twenty-four digital I/O lines with industry standard pinouts for solid state relay boards. Each line is software programmable as an input or output. The status of output lines may be monitored by software. Whenever a system reset occurs all output channels are turned off.

Software and Manuals

7421 Instruction Manual

Released 7/28/99

Specifications

Input resistance	100 Megohms
Max. input voltage	63 VAC rms
CMMR	95 db min
Max. command mode	+/- 5 volts
A/D converter	16-bit integrating
Conversion time	22 mS per channel
A/D scan rate	45 samples/sec
Operating temperature	-25°C to 85 °C
Interface	STD 80
Input power	5 volts at 100 mA
For Sensor Types, Resolution, Range and Codes click here
Sensor connector pinout

Images and Mechanical Drawings

Model 7421 Application

Prices

Model 7421	Analog & Digital Interface	Please call for availability
Model 7409C	18" analog cable, 40-pin	Qty:1 $14	Qty:2-9 $12
Model 7409C1	1 meter analog cable, 40-pin	Qty:1 $28	Qty:2-9 $25
Model 7409TB	Low cost analog screw terminal board	Qty:1 $65	Qty:2-9 $59
Model 7409TC	Screw terminal board with proto area	Qty:1 $105	Qty:2-9 $95
Model 7409TDIN	Screw terminal board with proto area and DIN snap rails	Qty:1 $140	Qty:2-9 $125
Model 7501C	18" digital cable, 50-pin	Qty:1 $17	Qty:2-9 $15
Model 7501C1	1 meter digital cable, 50-pin	Qty:1 $30	Qty:2-9 $27
Model 720RB	24 position relay board w/o DIN	Qty:1 $145	Qty:2-9 $130
Model 7505TDIN	24 position relay board with DIN snap rails	Qty. 1 $79	Qty. 2-9 $72
Model 720RB	Solid State Relay Board	Qty. 1 $145	Qty. 2-9 $130
Model 720RBDIN	Solid State Relay Board	Qty. 1 $180	Qty. 2-9 $165
Model 7502C	18" encoder cable, 20-pin	Qty. 1 $12	Qty. 2-9 $11
Model 7502C1	1 meter encoder cable, 20-pin	Qty. 1 $25	Qty. 2-9 $23
Model 7506TDIN	40 contact terminal board	Qty. 1 $79	Qty. 2-9 $72
Model 7505TDIN	50 contact terminal board	Qty. 1 $79	Qty. 2-9 $72
Model 7502TDIN	Screw terminal board with DIN snap rails	Qty. 1 $49	Qty. 2-9 $49