How to configure the device for communication with CRK via GSM modem? How to configure the device for communication with CRK via GSM modem? What to do if you enter the wrong tax office during fiscalisation? If the cash register communicates with CRK via Ethernet or WiFi, is it possible to use the same connection to communicate with the cash register from the computer (sales system)? Who is entitled to the deduction for the purchase of a cash register?