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The 427 is a Legacy product and is not recommended for new designs. The lead time for the 427 may be as long as 12 weeks and may require a minimum quantity order. Please call for availability.
Description
Model 427 interfaces four incremental encoders to the ISA bus. Three flat cables connect the Model 427 to external breakout boards.
Encoders
The four 24-bit up/down counter channels are optimized for incremental encoders. Each channel accepts two phased TTL or RS-422 signals, plus an index signal. Unlike conventional
counters, the 427 counters do not accumulate errors when the encoder dithers or changes direction.
Load-on-event
Each channel may be loaded with a preset count. The channels may also be programmed to load the preset count upon the occurrence of an index pulse, a terminal count, or a
match count.
The 427 supplies 5-volt power to all encoder channels. Each counter can be programmed to function as an encoder interface or as a general-purpose timer and may optionally generate interrupts. To
ensure maximum flexibility, no counter functions are used by any other onboard peripheral devices. The counters are double buffered to prevent data loss when reading accumulated counts.
Watchdog
The
427'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 427’s sixteen digital lines have standard pin-outs for solid-state relay boards. Each line is software programmable as an input or output. 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.
Interrupts
Each counter channel may be programmed to generate an interrupt upon detecting an index pulse, a preset or terminal count.
Digital I/O lines programmed as inputs may generate interrupts when their state changes.
Software and Manuals
A Windows NT/2000 driver is supplied with the 427.
427 Instruction Manual >> Released 4/2/01
427 DLL & Demo >> Released 4/2/01
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