EI-401 Four Encoder Interpolation Counter

EI-401 Four Encoder Interpolation Counter

PRODUCT OVERVIEW
The Model EI401 accumulates count information from four optical encoders. All four encoder's count information is then captured simultaneously upon a trigger event derived from the vertical sync pulse of a standard video signal or from a TTL pulse source. Interpolation of standard incremental encoders is 1, 2, or 4. With an analog encoder, interpolations range from 8 to 96. This means that with a 5,000 count analog encoder, the user has a maximum counts per revolution of 480,000.
[BLOCK DIAGRAM]

[USER'S MANUAL] (Rev. B, 618KB, 03/02/04)

ENCODER INTERFACE
Inputs for four encoders with quadrature Phase A, Phase B and quarter or half cycle positive going Index signals from industry standard optical encoders. Quadrature and index signals can be either 1 volt p-p differential analog or 5 volt square wave (differential or single ended). Maximum count rate is 500,000 counts per second quadrature x1 cycles. For differential mode the input impedance is 120 ohms. In single ended mode the input impedance is 10K ohms, field selectable.
VIDEO TRIGGER INTERFACE
0.5 to 2 V p-p standard negative going sync NTSC, PAL (European broadcast TV standard) and SECAM video signals. Video signal connector is a standard BNC with field selectable 75 ohm or high impedance termination.
SERIAL INTERFACE
Two serial ports, RS-422 and RS-232. Both ports transmit data to user's equipment but only one port can accept EI401 configuration commands. Serial format is default 38.4K, 8 bits, 1 start bit, 1 stop bit, and no parity bit, but is field changeable up to a maximum baud rate of 115.2K. Minimum delay from trigger event to start of serial data output is 1 millisecond. An additional delay to start of transmission maybe specified via a serial command, up to a maximum of 50 milliseconds.
COUNT CAPTURE JITTER
Maximum encoder count capture jitter is 75 nanoseconds from the Trigger event and 900 nanoseconds for an Internal Software Delay Trigger event.
POWER SUPPLY
Input power is 5 VDC 100mA (not including encoder power). The power to the encoders is protected by a 1.5 amp fuse which is field replaceable on the main PC Board.