I want to use Pololu High-Power Stepper Motor Driver 36v4 with only SPI interface. (No USB ). I would like to set up all necessery settings only once by means of Arduino. After this setting I want to use it as standalone drive using only STEP/DIR inputs. My question is: Is this setting permanent, or is it necessary to renew it after each switch off ?
It is not clear which product you are referring to; you mentioned both the Tic 36v4 and the High-Power Stepper Motor Driver 36v4, which are different products.
To clarify, the Tic 36v4 can be configured via USB and the configuration settings are saved in EEPROM so they are persistent through power cycles. The Tic does not have an SPI interface, but it supports a variety of control interfaces such as: USB, TTL serial, I2C, RC hobby servo pulses, analog voltage, quadrature encoder, or STEP/DIR inputs. However, please note that configuration settings saved in EEPROM can only be changed via USB.
The High-Power Stepper Motor Driver 36v4 uses an SPI interface, but the SPI configuration must be done each time the board is powered.