Siemens 6ES7403-1JA01-0AA0 SIMATIC S7-400 ER2 9-Slot PLC Rack

The Siemens 6ES7403-1JA01-0AA0 SIMATIC S7-400 ER2 rack is a 9-slot extension rack for signal modules only, carrying the P bus and accepting two redundant power supplies. It measures 257.5 mm wide by 290 mm high by 27.5 mm deep and weighs 2.2 kg. Rated ambient operating temperature is 0 to 60 degrees C.

Technical Specifications

Certifications & Standards

• CE
• UKCA
• UL
• FM
• RCM
• KC
• EAC
• CCC

Selection Notes

The ER2 carries only the P bus and holds signal modules, not a CPU or communication processor, so it extends I/O capacity on an existing central rack rather than adding controller functions. Its 9 slots and dual redundant power supply option fit a mid-size I/O extension; pick the larger extension rack instead when more signal-module slots are needed in a single expansion.

Applications

Because the ER2 takes only signal modules, it is the rack to add when a central S7-400 rack has run out of I/O slots but still has spare communication or CPU capacity. The two redundant power supply positions keep the added I/O powered if one supply fails, useful where the added signal modules serve process-critical measurements. At 257.5 mm wide it fits alongside the central rack in the same cabinet section without extra mounting depth.