Signal integrity realities
The 6AG1321-7TH00-4AB0: Unshielded cable is not permitted on these inputs — a hard stop. Shielded runs max out at 400 metres with an 18 V sensor supply, but drop to 200 m if you're using the 8.2 V rail (e.g. for NAMUR proximity switches). Plan cable lengths accordingly before the pull. The module issues wire-break and short-circuit alarms, plus a hardware interrupt and diagnostic alarm. That means you don't chase intermittent contacts blindly — the SF (red) group error trips immediately. Signal current for NAMUR is 2.1 to 7 mA typ.; a 10k/47k contact lands around 10 mA. If the current looks off, check the shield first — it's noise till proven otherwise.
Sourcing and compliance
This module carries CE, UL (File E239877), KC, EAC, and RCM approvals — covers most global markets for a panel build. The CE mark implies EU compliance.