What it is and what it does
The Siemens 6ES7422-5EH10-0AB0 is a 16-channel digital output module for the S7-400 programmable logic controller family. It provides switched DC outputs rated at 1.5 A per channel, with a permissible load voltage range of 20 V DC to 138 V DC. That wide compliance voltage means the module can drive a mix of 24 V DC, 48 V DC, and 110 V DC loads from a single rack — useful when a panel controls valves, contactors, or indicators at different voltage levels without separate interface relays. Each output is electronically short-circuit protected with a clocked current-limiting response. The typical fault threshold lies between 0.4 A and 5 A, so a dead-short on one channel will not cascade across the group of eight. Diagnostic alarms are parameterizable and readable via the backplane bus — the module reports internal faults (INTF, red LED) and external faults (EXTF, red LED) separately, which helps a commissioning engineer isolate a wiring fault from a module failure without pulling the card.
Key ratings and what they mean for your panel
The headline current rating is 1.5 A per channel, but the module's total current is thermally constrained. At up to 40 °C ambient the module can deliver 16 A across all outputs simultaneously (21 A with the optional fan assembly). At 60 °C the total drops to 8 A (14 A with fan). That derating curve is the real selection parameter: if you need all 16 channels at 1 A each in a sealed, non-ventilated enclosure, you must stay below 40 °C or add the fan. The 10 W typical power loss feeds directly into your enclosure thermal budget. Switching speeds are moderate: 2 ms turn-on, 13 ms turn-off. Resistive loads can be switched up to 10 Hz; inductive loads (solenoids, contactor coils) are limited to 0.5 Hz due to the energy-recirculation time. For fast-pulsing applications like a high-speed pick-and-place, this module is not the right fit — look to a S7-1500 digital output with shorter cycle times. The module occupies a single-wide slot (25 mm) in the S7-400 rack, with dimensions 210 mm deep and 290 mm high. It draws up to 700 mA from the 5 V DC backplane bus. Isolation between channel groups (groups of eight) and between the channels and the backplane bus is tested at 1 500 V AC, which is standard for industrial control panels operating on ungrounded or IT power systems.