I’m a student focusing on industrial control using 5G, and I’m building a private 5G network to enable communication between two PLCs using Quectel RM500Q-GL modules.
My current network topology is as follows:
【PLC1(192.168.0.1)—Ethernet Cable–RM500Q-GL1（10.45.0.101）—Wireless—5GC （SDR）—Wireless—RM500Q-GL2 （10.45.0.102）—Ethernet Cable—PLC2（192.168.0.2）】
Current status:
- Successfully established a private 5G network
- Both RM500Q-GL modules connect to the network and obtain IP addresses (10.45.0.100 and 10.45.0.101)
- The modules can ping each other and access both the gateway (10.45.0.1) and the internet
- Each PLC has a fixed IP address (192.168.0.1 and 192.168.0.2) and connects to its respective 5G module via Ethernet
- The PLCs cannot communicate with each other
## Problem Description
- Inconsistent AT Command Documentation: The responses from AT+QMAP=? and AT+QETH=? commands don’t match the official documentation. Some features mentioned in the documentation aren’t supported by the modules, while other supported features aren’t documented.
- Unclear Network Configuration Mode: It’s difficult to determine which mode (IP passthrough, router mode, bridge mode) is appropriate for enabling PLC-to-PLC communication.
- Confusing Routing/Bridging Functions: The AT+QETH=“routing” command exists but its purpose is unclear. The parameter format is restricted to
AT+QETH="routing",add,4,8.8.8.8,3, which only allows specifying a single IP address rather than a complete routing rule (source, destination, gateway, etc.). - IPPT and RGMII Configuration Ambiguity: There are contradictions and unclear instructions regarding AT+QMAP=“MPDN_rule” configuration parameters for IP passthrough (IPPT) and RGMII settings.
- PLC Fixed IP Challenge: The PLCs use fixed IP addresses (192.168.0.1 and 192.168.0.2) and don’t seem capable of obtaining IP addresses assigned by the 5G network.
Requirements
I need to enable communication between two PLCs with fixed IP addresses (192.168.0.1 and 192.168.0.2) through the RM500Q-GL modules over a private 5G network.
Specific questions:
- Which mode (IP passthrough/router/bridge) is most suitable for this scenario?
- What is the correct configuration for the RM500Q-GL modules to enable inter-PLC communication?
- Do the modules support sufficient routing capabilities to allow forwarding between different subnets?
- Are additional network devices (like routers) needed to accomplish this?
Currently, each module works normally in isolation for HTTP/TCP/UDP and ping functionality, but I cannot achieve cross-module communication between the PLCs.
Any help or suggestions from Quectel experts would be greatly appreciated!
RM500Q-GL 5G模块PLC通信问题求助
背景
我正在搭建一个私有5G网络环境，使两台PLC通过5G模块进行通信。目前网络拓扑如下：
【PLC1(192.168.0.1)—以太网—模块1（10.45.0.x）—无线—5GC—无线—模块2 （10.45.0.y）—以太网—PLC2（192.168.0.2）】
- 已成功搭建私有5G网络，两台RM500Q-GL模块可以获取IP地址(10.45.0.100和10.45.0.101)
- 模块可以互相ping通，也能访问网关(10.45.0.1)和互联网
- PLC分别使用固定IP地址192.168.0.1和192.168.0.2，通过以太网连接到5G模块
- PLC之间目前无法通信
问题描述
-
AT命令与文档不匹配：模块返回的AT+QMAP=?和AT+QETH=?命令结果与官方文档不符，部分功能未在文档中说明，部分文档中的功能模块不支持。
-
网络配置混乱：很难确定应该使用哪种模式(IP透传、路由模式、桥接)来支持PLC通信。
-
路由/桥接功能不明确：AT+QETH="routing"命令存在但用途不明，参数格式限制为
AT+QETH="routing",add,4,8.8.8.8,3，只能指定单一IP而非完整路由(源地址、目标地址、网关等)。 -
IP透传与RGMII配置模糊：关于IPPT(IP透传)和RGMII的AT+QMAP="MPDN_rule"配置参数存在歧义。
-
PLC固定IP难题：PLC使用固定IP地址(192.168.0.1和192.168.0.2)，似乎无法获取5G网络分配的IP地址。
需求说明
我需要实现两台固定IP地址(192.168.0.1和192.168.0.2)的PLC通过连接到RM500Q-GL模块的方式，在私有5G网络中实现相互通信。
具体问题:
- 应该使用什么模式(IP透传/路由/桥接)最适合该场景？
- 如何正确配置RM500Q-GL实现PLC之间的通信？
- 模块是否支持足够的路由功能允许不同子网之间的转发？
- 是否需要额外的网络设备(如路由器)来辅助实现？
目前，单独测试每台模块均可正常使用HTTP/TCP/UDP和ping功能，只是无法实现PLC之间的跨模块通信。
感谢专业人士提供的任何帮助和建议！
