SIPLUS CP 340 — conformal-coated RS-232 for harsh environments
The Siemens 6AG1340-1AH02-2AE0 is a SIPLUS variant of the S7-300 CP 340 communications processor, based on the standard 6ES7340-1AH02-0AE0 but with conformal coating and an extended ambient temperature range of -40 to +70 °C. This makes it the choice for installations where the standard CP 340 would exceed its rated limits — cold storage, outdoor cabinets, or unventilated enclosures near process heat.
RS-232C interface and protocol support
One isolated RS-232C (V.24) interface is provided via a 9-pin sub-D connector. The CP 340 supports ASCII protocol up to 9.6 kbit/s and 3964(R) protocol up to 19.2 kbit/s, with a 1 024-byte buffer for each. RK 512 is not supported. The transmission rate is configurable from 2.4 to 19.2 kbit/s. Maximum cable length is 15 m. The module draws up to 165 mA from the 5 V backplane bus, with a typical power loss of 0.6 W and a maximum of 0.85 W.
Environmental ruggedness and approvals
The conformal coating protects against condensation and corrosive gases. The module meets ANSI/ISA-71.04 level GX Group A/B (excluding trichlorethylene), level LC3 (salt spray), and level LB3 (oil). Installation altitude is rated up to 5 000 m with derating above 2 000 m.