JVL MIS17 Series, User Manual

Page: 110 / 367

110 JVL Industri Elektronik A/S - User Manual - Integrated Stepper Motors MIS17x, 23x, 34x, 43x
5.4 Absolute position back-up
5.4.4 Setup position backup NOT using MacTalk
An hardware improvement have been made on newer motors having a serial number (la-
bel at motor will tell) >SN173000. Before and after serial number 173000 the MIS motor
therefor have a different functionality.
Only MIS34x and MIS43x: Serial numbers < 173000 or HW<V1.6:
See also How to get SW/HW motor info , page 89 to obtain this information.
The absolute position backup system is activated when a voltage goes under a level, de-
fined by SAVE_VOLTAGE (register 141).
Then all absolute multiturn information is saved to the flash memory at once.
When power is applied again all data are recalled from the flash memory and the motor
can start operating based on the actual position that it had before power down.
It is required that the supply control voltage drops relatively slowly to allow time to save
the values to flash memory. This can be secured by adding, if necessary, a large capacitor
on the CVI supply voltage and powering on/off the external power supply on the AC side.
Beside the position information also the Event log information is saved. This is very help-
ful for later troubleshooting.
Only MIS34x and MIS43x: Serial numbers < 173000 or HW>V1.5:
See also How to get SW/HW motor info , page 89 to obtain this information.
The absolute position backup system is active all the time and is saving the absolute multi
turn position data once every second. This feature is based on a relatively new memory
technology called FRAM (Ferroelectric RAM) and no battery backup is involved.
If suddenly the supply power is removed and the motor stay within half a revolution dur-
ing power down the position is valid. If the motor was running during power down the
position data is probably invalid.
When power is applied again all data are recalled from the memory and the motor can
start operating based on the actual position that it had before power down.
Beside the position information also Event log information is saved. This is very helpful
for later troubleshooting.
5.4.5 Registers involved
Register 141 ,
Save Threshold Voltage, selects the voltage threshold, that will trigger the flash backup
save operation (and stop all other motor operation).
When register 142 has the value 12, the scaling/unit of register 141 is the same as register
97, Bus Voltage (4095 = 111.4V).
The register 142 has the values of 1-8 or 81-88, the scaling/unit of register 141 is the
same as registers 81-96 (4095 = 5.0V)
Register 139 ,
Acceptance Voltage, selects the voltage threshold that defines when the power supply is
ready to use for erasing flash memory after power up. The scaling/unit is the same as reg-
ister 141.
Only MISxxx--- H2 ---