Multiple HMIs connecting to one PLC
Technical Note 5033
Applicable Model(s)
HMI5000 Series
cMT Series
RMI5010
Title
Multiple HMIs connecting to one PLC
Date
10/04/2022
Rev
03
P/N
0907-5033
Summary
Several Graphic HMI units can be connected to one PLC as shown below. The HMI’s can also directly share data.
Solution
Local HMI Software Setup
To set up the Local HMI (master HMI), use EBPro and follow the steps listed below:
1.
After starting a new project for the local HMI, select Home > System Parameters. When the System Parameter Setting dialog box appears, select the Device tab and click New Device/Server… The Device Properties dialog box is displayed.
2.
In the Device Properties dialog box, ensure the Location is set to “Local” then select the appropriate communications driver – in this example Allen-Bradley SLC500 and Micro (DF1 Serial-CRC) is selected. Click Settings to display the COM Port Settings dialog box shown below.
3.
Adjust the communications parameters as needed to match the PLC settings, and those outlined in the appropriated Controller Information Sheet found on our website. When finished, click OK on all open windows to accept changes. This completes the communications setup of the local HMI (master HMI).
Remote HMI 1 Setup
1.
After starting a new project for the first remote HMI, go to the System Parameters and select New Device/Server, as was done in steps 1 and 2 of the local HMI set-up. Select Remote for the Location (see below). Click the Location Settings… button to display the IP Address Settings dialog box.
2.
Enter the IP address of the Local HMI (each HMI needs to have an IP address assigned to it in order to download to it). This should be the IP address of the device that we just configured, which is connected directly to the PLC.
3.
Select the PLC Type (communications driver) that the Local HMI is connected to. In the above example, Allen-Bradley SLC500 and Micro (DF1 Serial-CRC) has been selected. Click the PLC type Settings… button to display the COM Port Settings dialog box.
4.
Verify that the COM port selected is the COM port used by the Local HMI for communications to the PLC. Click OK on all open screens to save settings. This completes the communications set up of Remote HMI #1.
Remote HMI 2 Setup
After starting a new project for the second remote HMI, follow the steps for setting up Remote HMI #1. The configuration should be wired as follows:
Local HMI
For this example, the cable used connects COM port 1, via RS232 to Allen-Bradley MicroLogix or SLC500 PLC. The Ethernet port is connected to an Ethernet switch (straight through cable type).
Remote HMI 1
For this example, the Ethernet port of Remote HMI 1 is connected to an Ethernet switch (straight through cable type).
Remote HMI 2
For this example, the Ethernet port of Remote HMI 2 is connected to an Ethernet switch (straight through cable type).
Summary of Connecting cMT Series Devices to Remote HMI
Maple Systems has always had a simple method for communicating between HMI products. An HMI is simply added to an EBPro project as a ‘remote’ HMI, as demonstrated above. With the addition of our cMT series (as well as the older RMI series), another step has been added.
cMT as the Communications Master (cMT unit Polls Other Models)
In each device that is to be polled by a cMT unit, this new protocol must be included in the project. This is accomplished by checking a box on the Model tab of the System Parameters dialog as shown below:
In the project for the HMIs that will be polling the cMT device, the cMT must be added as a Remote HMI.
