Synchronous Serial Interface; Shift Register Operation; Example-Script - DEUTSCHMANN AUTOMATION UNIGATE IC - EtherCAT Instruction Manual

Synchronous serial interface

5 Synchronous serial interface
The synchronous serial interface of the UNIGATE
or components that have a Serial Peripheral Interface (SPI).

It allows
• the expansion of the IC for digital inputs and outputs (for example for driving LEDS or for rea-
ding switch positions)
• communicate with microcontrollers or
• the control of DA and AD converters.
Connection examples are give in chapter 3.
By using the synchronous serial interface can realize products that can work without another
microcontroller (stand-alone mode). Examples are sensor products or digital IO modules
5.1

Shift register operation

Before the interface can be used, it has to be initialized by setting various Script parameters.
(see chapter 5.1.1)
The parameters „ShiftRegisterInputType" and „ShiftRegisterOutputType" allow the
use of different shift register types, which differ in the polarity of the shift register signals. To use
the shift register types 74595 and 74165, for example, the values „RiseClk_RiseLoad" and
„RiseClk_LowLoad" can be set.

The shift register width is set by the parameter „ShiftRegisterInputBitLength" and
„ShiftRegisterOutputBitLength" The maximum width is 256 bits.

The data exchange with the connected shift registers ensues with the commands
hiftRegister", „ReadShiftRegister" or bidirectional with the command
sterDataExchange". The clock rate is between 280 kHz and 320 kHz.

Further information on the commands and parameter values can be found in the Help section of
the Protocol Developer Software. On request, the Deutschmann Script language can be comple-
mented by additional parameter values in order to support other types of shift registers.
5.1.1

Example-Script

Note: The script example refers to the circuit example in chapter 3.5.
var InBuffer: Buffer[2];
var OutBuffer: Buffer[2];
MoveConst( OutBuffer[0], #0x58#0x21 );
Set( ShiftRegisterInputType, RiseClock_FallLoad );
Set( ShiftRegisterOutputType, RiseClock_RiseLoad );
25 UNIGATE
®
®
fieldbus gateway UNIGATE
Deutschmann Automation GmbH & Co. KG
IC is used to connect clocked shift registers
® ®
IC - EtherCAT V. 2.6
„WriteS-
„ShiftRegi-
30.9.20