The ControlLogix or CompactLogix MSG block is displayed as follows. More detailed information on the MSG block is available in Allen Bradley publication 1756-RM003L-EN-P, Logix5000 Controllers General Instructions.

 

The Message Control portion of the MSG requires a tag.
To create a tag:

• Right-click the "?" and choose NewTag.

• Type a name in the Name field.

• Make sure the Data Type is MESSAGE.

• Click Configure. The Message Configuration dialog will open.

• Enter the following on the Configuration tab:

• • Message Type: From this drop-down list, select SLC Typed Read to read values from the RMC, or SLC Typed Write to write values to the RMC. The PLC-5 Typed Read or Write will also work, and is required for transfers of more than 58 registers.

  • Source Element (reads only): Enter the address of the first RMC register you want to read. See the Registers Maps for help on addresses.

  • Source Element (writes only): Enter the tag in the ControlLogix or CompactLogix that you want to send to the RMC. In most cases, the element should be an array or structure composed entirely of REAL data types, since this is the type of the RMC data.

  • Number of Elements: Enter the number of RMC registers to read or write in this field. The ControlLogix and CompactLogix limit this to approximately 58. For larger transfers, use the PLC-5 Typed read or write.

  • Destination Element (reads only): Enter the tag in the ControlLogix or CompactLogix into which you want to read the RMC data. See the Source Element bullet above for suggestions on the data type of the tag.

  • Destination Element (writes only): Enter the address of the first RMC register you want to write. See the Registers Maps for help on addresses.

• Enter the following on the Communication tab:

• • For Ethernet:
    Path: Enter the path from the ControlLogix or CompactLogix CPU to the RMC. The format of the path usually is as follows:

[Ethernet module name], 2, [RMC IP Address]

To get the Ethernet module name, click the Browse button and select the Ethernet module. The "2" specifies the Ethernet port on the module.

Therefore, if a ControlLogix 1756-ENBT is in named LocalEnb, and the RMC is at address 192.168.0.5, then the following path would be used:

LocalENB, 2, 192.168.0.5

 

Note: If you are also using EtherNet/IP I/O cyclic messaging, you can use the name of the name you assigned to the Generic Ethernet Module that references the RMC. This name will constitute the entire Path.
For example, if you assigned the name MyRMC, then the Path would be: MyRMC.

 

If the Logix5000 project I/O configuration does not include the module name, you will need to give the path of going over the Logix backplane to the Logix ethernet communication module and then going over the Ethernet to the RMC. The backplane is indicated by the number "1". The path would then be:

1, [Ethernet module slot number], 2, [RMC IP Address]

Therefore, if the 1756-ENBT is in slot 3 (the third slot on the rack), and the RMC is at address 192.168.0.5, then the following path would be used:

1, 3, 2, 192.168.0.5

1. • For Serial:
     Path: Enter the path from the ControlLogix or CompactLogix CPU to the RMC. The format of the path usually is as follows:

2, station address

where station address is the node address of the RMC. For example, if the node address is 3, the path is:

2, 3

Note:
The "2" is the port number for the serial port on the ControlLogix CPU.

 

• • Communication Method: Select the CIP option.

• Click OK.

• To make changes to the Message Configuration dialog later, click the ellipsis button in the MSG block.

 

The SLC 5/05 MSG block is displayed as the following:

 

Parameter	Description
Type	This parameter is always set to Peer-To-Peer for serial or Ethernet communication channels.
Read/Write	This parameter should be set to Read to read registers from the RMC and to Write to write registers to the RMC.
Target Device	This should be set to 500CPU for communicating with the RMC.
Local/Remote	This parameter has possible values of Local and Remote. It should be set to Local for communicating with the RMC.
Control Block	This parameter points to a block of integer-file registers (51 registers for Ethernet, 12 for serial).  Set this to a block of registers, and then use the Setup Screen option in the MSG ladder logic block to modify those register values: This Controller: This section holds parameters for the SLC 5/05. Communication Command: This parameter will be set to 500CPU Read, or 500CPU Write, depending on what was selected in the MSG block itself (as described above). Data Table Address: Enter the address of the first Allen-Bradley PLC register to read RMC registers into, or to write to RMC registers from. Size in Elements: Enter the number of RMC registers to read or write in this field. The range enforced by the SLC is 1 to 256 values. Channel: Set this to the channel number of the serial Ethernet channel. For the SLC 5/05, this should be channel #1 for both serial and Ethernet. Target Device: This section holds parameters for the target device. Message Timeout: Indicate the number of seconds to wait for the RMC to respond before determining that the attempt failed. This can be set as low as a few seconds. Data Table Address: Enter the address of the first RMC register to read or write in this field. See the RMC Register Map (Allen-Bradley) for help on addresses. For Ethernet: Ethernet (IP) address: Set this to the IP address of the RMC you wish to communicate with. MultiHop: This parameter should be set to No. For Serial: Local Node Addr (dec): Enter the node address of this RMC. The node address of the RMC is set up in the Serial Port Settings Page. The node address entered on that screen is in decimal, so it is recommended that you enter the same number in the dec field. Local/Remote and Bridge Parameters: In most applications these will be set to Local and there will be no bridge parameters. If you are using a bridge then these parameters will need to be used. However, this is beyond the scope of RMC documentation. Refer to your Allen-Bradley documentation for instructions on using these fields.

 

Note:
For the SLC505, if the start of communications with the RMC exhibits several minutes of delay after power-up, it is because your SLC processor and/or firmware is old. Newer SLC processors do not have this problem.

The PLC-5 MSG block is displayed as follows:

The Control parameter points to a block of 51 N-file (integer) registers or two (2) MG-file (message) registers. Set this to an unused block of registers, and then use the Setup Screen option in the MSG ladder logic block to modify those register values:

Register	Description
This PLC-5	This section holds parameters for the PLC-5: Communication Command: From this drop-down list, select PLC-5 Typed Read to read values from the RMC, or PLC-5 Typed Write to write values to the RMC. Data Table Address: Enter the address of the first Allen-Bradley PLC register to read RMC registers into, or to write to RMC registers from. Size in Elements: Enter the number of RMC registers to read or write in this field. Transfers are limited to 1000 bytes for PLC-5 Typed Reads and Writes. Therefore, this limit is 500 integers, 250 floats, etc. Port Number: Set this to the Ethernet channel number. For the PLC-5, this should be channel #2.
Target Device	This section holds parameters for the target device: Data Table Address: Enter the address of the first RMC register to read or write in this field. See the Registers Maps for help on addresses. For Ethernet: MultiHop: This parameter should be set to No. Ethernet (IP) address: Set this to the IP address of the RMC you wish to communicate with. For Serial: Local Node Addr (dec): Enter the node address of this RMC. The node address of the RMC is set up in the Serial Port Settings Page. The node address entered on that screen is in decimal, so it is recommended that you enter the same number in the dec field.

 

The MicroLogix MSG block is displayed as follows:

Serial Communications:

To edit the parameters of the message block, select the MSG block, enter an unused MSG file in the MSG File parameter, and double-click Setup Screen. This brings up a dialog with the following options:

This Controller: This section holds parameters for the MicroLogix.

Communication Command: This parameter can be set to PLC5 Read, PLC5 Write, 500CPU Read, or 500CPU Write.  The type of PLC selected is not important, but the Read or Write determines whether you will read registers from the RMC or write registers into the RMC.

Data Table Address: Enter the address of the first Allen-Bradley PLC register to read RMC registers into, or to write to RMC registers from.

Size in Elements: Enter the number of RMC registers to read or write in this field.  The MicroLogix can transfer 1 to 41 integers.

Channel: Set this to the channel number of the serial port you want to use.  The MicroLogix 1500 LRP Series B can use either channel 0 or 1, but all other MicroLogix PLCs will always use channel 0.

Target Device: This section holds parameters for the target device.

Message Timeout: Indicate the number of seconds to wait for the RMC to respond before determining that the attempt failed.  This can be set as low as a few seconds.

Data Table Address: Enter the address of the first RMC register to read or write in this field.  See the Registers Maps topic for help on addresses.

Local Node Addr (dec): Enter the node address of this RMC. The node address of the RMC is set up in the Serial Port Settings Page. The node address entered on that screen is in decimal, so it is recommended that you enter the same number in the dec field.

Local/Remote and Bridge Parameters: In most applications these will be set to Local and there will be no bridge parameters. If you are using a bridge then these parameters will need to be used. However, this is beyond the scope of RMC documentation. Refer to your Allen-Bradley documentation for instructions on using these fields.

 

Ethernet Communications (MicroLogix 1100):

1. In the RSLogix project tree, in the Data Files, create a message File (MG) data file and a Routing Information (RI) data file.

2. Add the MSG block to the ladder logic. Select the MSG block, enter the an address in the Message data file you just created (e.g MG9:0), and double-click Setup Screen.

This brings up a dialog with a General tab the following options:

This Controller: This section holds parameters for the MicroLogix.

Channel: To use Ethernet on the MicroLogix 1100, choose 1 (integral).

Communication Command: This parameter can be set to PLC5 Read, PLC5 Write, 500CPU Read, or 500CPU Write.  The type of PLC selected is not important, but the Read or Write determines whether you will read registers from the RMC or write registers into the RMC.

Data Table Address: Enter the address of the first Allen-Bradley PLC register to read RMC registers into, or to write to RMC registers from.

Size in Elements: Enter the number of RMC registers to read or write in this field.

Target Device: This section holds parameters for the target device.

Message Timeout: Indicate the number of seconds to wait for the RMC to respond before determining that the attempt failed.  This can be set as low as a few seconds.

Data Table Address: Enter the address of the first RMC register to read or write in this field.  See the Registers Maps topic for help on addresses.

Local / Remote: Choose Local.

Routing Information File (RI): Enter the address in the Routing Information File that you intend to use (e.g. RI10:0).

 

3. On the Multi-hop tab, in the To Address box, enter the IP address of the target RMC. For example, 192.168.0.219.