RICHMOND, Calif., March 2013 — Mesa Electronics’ 4I74 is a stackable PCI/104 card with eight quadrature up/down counters and count inputs, quadrature edge time stamping for velocity estimation, and per-channel index inputs.
The card has selectable TTL or RS-422 levels on its quadrature and index inputs, and is jumper-selectable on a per-input basis. The differential RS-422 inputs are suited for longer cable lengths and are terminated. Eight RS-422 serial ports are provided. Two ports can be run in RS-485 mode and can be used for asynchronous serial communication, SSI or BISS encoder interfaces, Mesa Smart serial remote I/O communication or other tasks, depending on FPGA firmware.
The encoder connectors are compatible with the 4I30 and 4I36. Programmable digital filtering is used on encoder inputs to reject input noise. The 4I74 counters may cleared individually. Each counter has an option to be cleared or latched by either the rising or falling edge of the index signal.
Maximum count rate with TTL inputs is 4 million per second, and maximum count rate with RS-422 inputs is 10 million per second. The 4I74 uses an FPGA chip for all counting and I/O, enabling easy upgrade or modification in the field for specific requirements. The flash memory can be updated from the host; no special cable or adapters are required.
Applications include robotics, motor control, measurement and instrumentation.
For more information, visit: www.mesanet.com