Accessories for ACT20 Series Isolating Converters. Accessories for analogue signal processing products such as ACT20 Series Isolating Converters. Connection Terminals Connection Terminals ( ; 902-8048 902-8048 ; ; 902-8057 902-8057 ) to be used with ACT20X isolating converters for external cold-junction compensation. Cold-junction compensation is required when using thermocouples for temperature measurement. USB Interface Cable USB Interface cable ( ; 902-8050 902-8050 ) for PC based configuration and calibration of the universal signal isolating converters, such as ITXPlus, WAVE, TTA and ACT20 series. The cable has a status LED for displaying the transmit/receive mode.