There are a large number of channels in the signal chain. Up to 100 ADC channels are required, depending on the system platform. Multi-channel, simultaneous sampling ADCs with wide dynamic range such as the AD7606, AD7607, AD7656-1, and AD7865 are used. The following complementary components for the simultaneous-sampling ADCs are available to complete the power-line monitoring signal chain: OP1177/4177 buffer transformer output; ADR421/ ADR291/ADR525 external reference, with isolation required between the central backplane and the data; and the ADUM1100/ADUM140x power lines to and from the signal conditioning board. The communications used to transmit the collected data can be over RS232, RS485, 4-20mA or sometimes Ethernet. Devices such as the ADM232A high-speed, driver/receiver and ADM1485 high-speed, ultra-low power transceiver, and either the AD5420 or AD5422 are excellent choices for 4-20mA transmission. Finally, the power management components include the ADP17xx and ADP1864 power management ICs.