JVL MIS23 Series, User Manual

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JVL Industri Elektronik A/S - User Manual - Integrated Stepper Motors MIS23x, 34x, 43x 73
5.3 Absolute position back-up
The absolute position backup system is activated when a voltage goes under a preset val-
ue. Then all absolute multi turn information is saved to flash at once.
All data are then recalled from flash memory at startup and the motor has the absolute
position information saved at power down.
The input on which the voltage drop is monitored, is selected between all standard I/O’s,
the P+ (12-48V power supply MIS23x or 12-80V MIS34x) and a special input (see the
“registers involved –section” later in this chapter).
When the operation is triggered, the motor will not be able to work at all until the power
has been cycled off and on again.
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 CV supply voltage and powering on/off the external power supply on the AC side.
Beside the position information also error tracking information is saved. This is very help-
ful for later troubleshooting.
5.3.1 Registers involved
Register 142 , Analogue Input Selection, selects which analogue input to use for meas-
uring the power supply. It can be:
1 to 8 for analogue inputs IO1 to IO8, using the unfiltered values for fast response.
81 to 88 for analogue inputs IO1 to IO8, using the filtered values for noise immunity.
12 for the 12-48V (12-80V MIS34x) power supply P+ and finally 13 for a special input
developed for this feature alone (from HW rev. 1.7 and up).
Any other value will disable the flash backup system.
When running the motor from 30 Volts or less, it can be convenient to connect the bus
voltage with the control voltage (CV) supply, and use the value 12 in register 142 to mon-
itor the control voltage.
When running the motor from 48 Volts, this is not allowed and can damage the controller
board if voltage exceeds 30V.
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 (1023 = 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 (1023 = 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 register 141.
Register 140 , Acceptance Count, selects the number of times the Acceptance Voltage
must be measured after power up before the flash erase operation is started.
When using values 1-8 or 12 for register 142, the count is in units of ~245 microseconds.
When using values 81-88, the count is in units of 10 milliseconds.
Register 124 , SetupBits, selects to use Flash-based Absolute Multi turn Encoder func-
tionality when bit 11 is set.
Only MISxxx--- H2 ---