Block

Mask

Description

Synchronous Serial Interface (SSI) is a widely used serial interface standard for industrial applications especially, rotary encoders. It is a point-to-point connection from a master (e.g. PLC, microcontroller or other control systems) to a slave (e.g. the rotary encoder). In this type of interface, the position data is continually updated by the sensor and made available to the output register.

The SSICommBlockMaster provides this capability to read position of the encoders.

Provide SSI Clock rate	Specify the Clock of the SSI interface. Option As Block Input: Add a port to the block in which user can set the period of the clock through the port. Option As Block Parameter: Add a new field in the GUI in which user can specify the period of the clock.
Provide Number of Bit Resolution	Specify the number of bits resolution. Option As Block Input: Add a new port to the block. User can set the number of bits throught this port. Option As Block Parameter: Add a new field in the GUI. User can specify the number of bits in this field.
Provide Bit Shift Pattern	Specify the shift patterm (MSB first or LSB first) Option As Block Input: Add a new port to the block. User can set the shift pattern throught this port. Option As Block Parameter: Add a new field in the GUI. User can specify the shift pattern in this field.
Provide Gray Encoded Info	Specify if the data is gray encoded or not Option As Block Input: Add a new port to the block. User can set the info throught this port. Option As Block Parameter: Add a new field in the GUI. User can specify the info in this field.
Provide TP Time	Specify the pause time. It is the time delay between two consecutive clock sequences. Option As Block Input: Add a new port to the block. User can set the time throught this port. Option As Block Parameter: Add a new field in the GUI. User can specify the time in this field.

Inputs

SSIClkDiv	This port is used to specify the SSI clock divider. The value is used to divide down the system clock to provide the SSI clock frequency. This port is available only when option As Block Input is chosen in the GUI.
TP_Time	This port is used to specify the pause time between two sequences of SSI clock. This port is available only when option As Block Input is chosen in the GUI.
BitRes	This port is used to specify the number of bit resolution. This port is available only when option As Block Input is chosen in the GUI.
MSBFirst	This port is used to specify the bit shift pattern. This port is available only when option As Block Input is chosen in the GUI.
GrayEncoded	This port is used to specify if the data is gray encoded or not. This port is available only when option As Block Input is chosen in the GUI.
SSIDataIn	SSI Serial data.

Outputs

SSIClkOut	SSI Clock output.
DATAOUT_VLD	This port indicates that data on port DATAOUT is valid.
DATAOUT	This port holds the value of the position of the encoder.

Block Handshaking

Receiving Data	The SSICommBlockMaster block asserts the DATAOUT_VLD when the data presents on the DATAOUT bus is valid.

Characteristics and Limitations

This Block has no specific characteristics or limitations

Direct Feedthrough	N/A
Discrete sample time	N/A
XHP support	N/A
Work offline	YES

RT-XSG Documentation

SSI Communication Master Interface