Siemens Ethernet modules CP343-1 and CP343-1 Lean: What are the differences?
Ethernet is increasingly prevalent in industrial settings, and Siemens PLCs offer two Ethernet communication solutions: one utilizes the CPU with an integrated PN interface for direct Ethernet communication, and the other employs dedicated Ethernet modules (CP343-1) for Ethernet communication. In this article, we will focus on the Ethernet module CP343-1 and address a common question: What are the differences between CP343-1 and CP343-1 Lean?
The CP343-1 module is an Ethernet communication module for the Siemens S7-300 series PLC (for the S7-400 series, the equivalent is CP443-1). The family of CP343-1 modules includes CP343-1 Lean and CP343-1 Advanced. The Lean version is a streamlined version of CP343-1, supporting a relatively smaller number of connections. However, its cost advantage (almost half the price of CP343-1) makes it widely applicable in scenarios with fewer connections. The Advanced version is the high-end variant of CP343-1, offering comprehensive Ethernet solutions but comes with a higher price tag. The diagram below illustrates the appearance of the CP343-1 family members:
CP343-1 is connected to the CPU via the backplane bus connector, featuring LED indicators on the front with the following meanings:
- SF (System Faults): Illuminates in red, indicating a system fault.
- BF (Bus Faults): Illuminates in red, signifying a fault in the Ethernet interface bus.
- DC5V: Illuminates in green, confirming the normal operation of the backplane 5V power supply.
- RX/TX: Receive/Transmit indicators. Illuminates when data is being received/transmitted.
- RUN: Illuminates in green, indicating the module is in operational mode.
- STOP: Illuminates in red, signaling that the module is in a stopped state.
- X1/P1: Port 1's connection and network status. Green signifies normal connection, while yellow indicates data transmission/reception.
- X1/P2: Port 2's connection and network status. Green denotes a normal connection, while yellow indicates data transmission/reception.
- MAINT: Illuminates when the module requires maintenance.
The image below shows a photo of CP343-1 Lean operating under normal conditions:
The most significant difference among the CP343-1 family members lies in the supported number of connections. Whether in S7 communication or Ethernet communication, the Lean version supports the smallest number of connections (the supported data block length is the same for all three versions).
A notable point to highlight is regarding the maximum number of Ethernet connections, which includes ISO-ON-TCP, TCP, or UDP protocols. For the Lean version, you can allocate all 8 connections to UDP protocols or have a combination of 6 UDP connections and 2 TCP connections. Regardless, the maximum number of connections is capped at 8.
While the Lean version supports fewer connections compared to the other two versions, it offers a significant cost advantage over CP343-1. Therefore, in scenarios where the number of connections is limited, CP343-1 Lean version finds widespread application.
That concludes the discussion on the CP343-1 module for now.