Delta RMC101 - Manual (Page 318)

RMC100 and RMCWin User Manual
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To edit the parameters of the message block, select the MSG block, and click on the button with
the ellipses to the right of the message tag name (msgReadStatus in the example above).
This will bring up a dialog with two tabs. Each is described below:
• Configuration tab:
o
Message Type: From this drop-down list, select PLC5 Word Range Read to read values
from the RMC, or PLC5 Word Range Write to write values to the RMC.
o
Source Element (reads only): Enter the address of the first RMC register you want to read.
See the RMC Register Map (Allen-Bradley) for help on addresses.
o
Source Tag (writes only): Enter the tag in the ControlLogix that you want to send to the
RMC. In most cases, the tag should be either an array or structure composed entirely of INT
data types. This is because both the RMC registers and the INT data type hold 16-bit binary
numbers. One issue to keep in mind is that the INT data types are always treated like signed
numbers with a range of -32768 to 32767, while the RMC registers are sometimes signed,
sometimes unsigned (0 to 65,535) and sometimes somewhere in between.
o
Number of Elements: Enter the number of RMC registers to read or write in this field. You
can transfer from 1-32767 registers at a time per MSG block. Reads or writes that extend
beyond the end of a register file will continue into the next register file or files. For example,
reading 2048 elements from N9:0 will read N9:0 to N9:255, then N10:0 to N10:255, on
through N17:255.
o
Destination Tag (reads only): Enter the tag in the ControlLogix into which you want to read
the RMC data. See the Source Tag bullet above for suggestions on the data type of the tag.
o
Destination Element (writes only): Enter the address of the first RMC register you want to
write. See the RMC Register Map (Allen-Bradley) for help on addresses.
o
Communication tab:
o
Path: You must enter the path from the Logix5550 CPU to the RMC. This path must, at the
minimum, include going over the rack to the 1756-ENET card and then going over the Ethernet
to the RMC. Therefore, the format of the path usually is as follows:
1, [1756-ENET slot number], 2, [RMC IP Address]
Therefore, if the 1756-ENET is in slot 2 (the third slot on the rack), and the RMC is at address
192.168.0.5, then the following path would be used:
1, 2, 2, 192.168.0.5
o
Communication Method: Select the CIP option.
o
Cache Connections: This checkbox is not used for the message type selected.
Using the MSG Block in Ladder Logic
The Allen-Bradley MSG block takes multiple ladder scans to complete. Therefore, it is important
to enable the MSG block for the correct amount of time. Specifically, the MSG block must be
energized until the message control's enable (EN) bit turns on. Delta has found some aspects of
this to be difficult and therefore has provided the following ladder samples:
Read or Write Continuously