Siemens 6ES7340-1AH02-0AE0 SIMATIC S7-300 CP 340-RS232C Communication Processor

Ready-to-Rack Summary

• Part Number: 6ES7340-1AH02-0AE0 (RS232C Point-to-Point Communication Module)
• Condition: Factory New Sealed in Original Siemens Packaging
• Warranty: 24 months (with full serial port & protocol test report)
• Availability: 24-hour worldwide dispatch from EU/US stock
• Interface: 1 × RS232C (V.24), max. 115.2 kbps, 15 m cable length

The Classic Serial Workhorse for S7-300 in 2025

Still the go-to module when you need rock-solid ASCII, 3964(R), or printer communication from an S7-300 CPU – no external converters required. Plants keep it in stock because:

• Direct connection to barcode scanners, weigh scales, inverters, HMI panels, and legacy controllers
• Built-in protocols: ASCII, 3964(R), RK512, and printer driver
• Freeport mode for custom protocols (FB/FC in STEP 7)
• Full diagnostics via LED and buffer in STEP 7 / TIA Portal 18

Failure Symptoms Triggering Immediate Replacement

Technicians order this exact card when:

• “CP 340 fault LED red” or no response on COM port
• Diagnostic buffer shows “transmission error” or “parity/framing”
• Barcode scanner or scale no longer sends data after years of 24/7 use
• Hot-swap fails due to internal EEPROM corruption

Real-World Deployments 2024–2025

• Packaging & Labeling: Videojet & Domino printers – direct string output
• Weighing Systems: Mettler Toledo & Sartorius scales – 3964(R) data exchange
• Third-Party Devices: ABB & Danfoss drives – ASCII parameter read/write

Technical Data Table

Compatibility

• Direct replacement for 6ES7340-1AH01-0AE0 and all AH revisions
• Works with all S7-300 CPUs (including F versions)