Mitutoyo tools utilize the proprietary Digimatic output format to transmit measurement data to computers, data loggers, or multiplexers. When the caliper's internal microprocessor attempts to send a signal through the output connector but encounters an interruption, a hardware conflict, or an incomplete circuit, it triggers the E--05 fault code. Common Causes of the E--05 Error

If you use your caliper near a running VFD (variable frequency drive on a milling machine), a large welding machine, or a powerful motor, the EMI can couple into the caliper's circuitry.

When this code appears, the caliper will lock all functions (zero-setting, data output, mode switching). It is not a user-recoverable error in most cases.