The I-7051 offers 16 channels for digital input, catering for both dry and wet contact, with an effective distance for dry contact of up to 500 meters. All channels not only feature Photocouple isolation, but can also be used as 16-bit counters. The I-7051D has 16 LED indicators that can be used to monitor the status of the digital input channels. 4 kV ESD protection and 3750 VDC intra-module isolation are standard. The M-7051 has the same hardware specifications as the I-7051, but provides additional support for the Modbus RTU protocol as well as the DCON protocol.