RS232C point-to-point link for legacy S7-300 racks
The Siemens 6ES7340-1AH01-0AE0 is a CP 340 communication processor that fits a standard S7-300 slot (40 mm wide, 125 mm high, 120 mm deep) and provides one isolated RS232C (V.24) interface. It handles ASCII and 3964(R) protocols with a 1 024 byte buffer each, topping out at 19.2 kbit/s — enough for printer links, scale readouts, or barcode scanners on older lines.
Lifecycle: end-of-line, sourced to order
For a new design or a line migration, the S7-1500 platform offers CPs with higher baud rates and Ethernet connectivity, but those require a different backplane and engineering environment.
What the baud and buffer mean for your device
The interface is isolated, which helps avoid ground loops when the serial device is on a different power circuit — a common headache on plant floors with mixed 24 V and 120 V gear.