Basic function principles

The KL5001 terminal is an SSI interface for the direct connection of an SSI encoder. The terminal outputs a clock burst for reading the encoder and makes the incoming data stream available to the controller in the process image. Various operation modes, transfer frequencies, bit widths and code implementations can be selected. The individual configuration is permanently stored in a register set.

The LEDs indicate the operating state of the associated terminal channels.

SSI principles

SSI communication sequence

The last data bit can be a PowerFail bit, i.e. the slave signals a power failure. This output depends on the slave.

The number of bit changes equals the clock frequency, i.e. the maximum data transfer rate for a 1 MHz cycle is 1 Mbit/s.

Referencing an SSI signal

An SSI encoder is an absolute encoder, which means, that the position value is available without referencing immediately after switching on.
Many SSI encoders offer the option of referencing or zeroing the position value via an additional digital input. Depending on the signal voltage of the digital input on the encoder, this can be set, for example via a digital output terminal EL2xxx.

Alternative process data output format

The SSI interface is delivered with a data width of 24 bits and activated Gray binary conversion in the alternative output format. The baud rate to the SSI encoder is set to 250 kHz. The process data are output in the input data bytes D0 - D3. The mapping of the terminal in the alternative format is described in more detail in the chapter Terminal configuration.

Standard output format of the process data

4 bytes of input data are mapped in the bus coupler in the standard output format in the delivery state.