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Positioning with external SSI encoder
Valid for S400, S600
Setup must be done with a terminal software or with the setup software in the terminal screen page.
|DIS||switches software enable off|
|EXTPOS 1||Position feedback => with external position encoder|
|GEARMODE 7||Selection of the measuring system => SSI|
|ENCMODE 2||Emulation mode of the ROD / SSI interface (with GEARMODE=7 always 2 with SSI encoder )|
|SSIGRAY 0 or 1||Data format according to SSI protocol 0=binary / 1=gray|
|SSIINV 0 or 1||Transmission of MSB (=0) first or LSB (=1) first|
|SSIMODE 0||Alarm bit at the beginning (=1) or at the end (=2) or none (=0)|
|SSIOUT x||x = number of data bits +1|
Internal factor: y = sz / (encoder resolution in increments)
|Finish the setup with|
|SAVE||saves parameters in the EEPROM of the servo amplifier|
|COLDSTART||restarts the amplifier, required to enable parameter changes|
It must be guaranteed that one revolution of the position controller set point produces one revolution of the position controller actual value. Possible procedures for the adjustment are described on page "Speed adjustment with external position feedback" described.
Parameter overview see page Parameters for SSI Interface.
A reference task (homing) is not required, because the SSI encoder is an absolute measuring system.
- Move the servo axis after restart to the required zero position.
- Read the actual position with the command PFB inthe terminal screen
- Set ROFFS = -PFB
- Save the parameters with SAVE and restart the amplifier with COLDSTART. PFB is now = 0.
- check phase position !
- check signal form of data and clock signals: should be similar to the above diagram. Number of data bits and clock bits can differ due to the software setup.
- Start an external terminal software (e.g. HYPER TERMINAL). Setup: 9600 baud, 8 bit, 1 stop bit, no parity, no handshake
- If your command looks like this: o -- >, then send the command PROMPT 133
- Send the commands
- You can evaluate the SSI data which have been received by the amplifier by the ASCII command M NEWSSI. The information is shown hexadecimal in LONG FAST format.
- Incorrect EXTMUL setting can result in wrong position monitoring