TPMC317

TPMC317 6 Channel SSI, Incremental Encoder, Counter

Six independent channels. Each of these channels can operate as a standard SSI interface controller, in a SSI ‘Listen only’ mode, as an incremental encoder or general purpose counter.

The standard SSI interface controller outputs a clock burst to the absolute encoder and receives the returned
positional data. The SSI interface controller operates with a programmable clock rate from 1μs to 15μs and programmable data word length from 1 bit to 32 bit.

In ‘Listen only’ Mode the channel listens to an existing SSI interface to observe its data transfer. It takes both the SSI clock and data as inputs. In ‘Listen only’ Mode the channel also has a programmable data word length from 1 to 32 bit; the SSI clock rate of the observed SSI interface may be in the range of 66,7 KHz to 1 MHz.

In both modes the data word can be encoded in binary or in Gray code and with odd, even or no parity. The 32 bit incremental encoder counter is a preloadable up/down counter. The counter is programmable for single, double and quadruple analysis of the encoder signals. In conjunction with the isolated 24V digital inputs it provides the possibility of automatic preload of the counter whenever the motion system passes a reference position. The 32 bit general purpose preloadable up/down counter can be fed with an internal clock or with external signals. Both counter modes offer a 32 bit preload register, a 32 bit compare register and various count modes.

A 'Multiple Channel Read' function latches the actual values of all enabled channels whose values can then be read without interfering with normal function. In addition the TPMC317 provides a 16 bit down-counter with preload register which allows timing intervals of up to 65ms. It can be used as reference timer for closed loop applications or as trigger for the Multiple Channel Read function.

All data inputs are isolated. The level of the input signals
can be RS422 or TTL. The input signals pass a digital filter for noise suppression. The level of the SSI clock output signals is RS422. Each of the six motion control channels of the TPMC317 offers one isolated 24V digital input. The input circuit ensures a defined switching point and protection against confusing the pole. The input has an electronic debounce circuit. All six 24V digital inputs can generate interrupts, triggered on rising or falling edge. Depending on the selected mode the input can be used as general purpose input or reference input.

A wide range of drivers is available: Linux, QNX, VxWorks and Windows. All drivers - except the Windows drivers - are supplied as C source code.