Toyopuc PC3/PC2 Ethernet Driver
Tag Name Functional Description
preferably 1. This is a signed long and will roll over.
Note: All diagnostics tags are Read/Write. The only value that can be written to the tags is zero (which will
clear or reset them).
Multi-Point Read Support
The Toyopuc PLC supports the ability to read data spread randomly throughout the PLC using a single
command. By using this command, users can read crucial data items quickly and efficiently. The Toyopuc
PC3/PC2 Ethernet Driver automatically attempts to make the use of the multi-point command both easy and
efficient. Any memory type that can be acquired by the Toyopuc PC3/PC2 Ethernet Driver can be part of a
multi-point read command. To mark a particular data item to be part of a multi-point request, place the '#'
character in front of any current address. The table below is shown with the addition of the '#' character to
each address. For information on the maximum data that can be read with a multi-point command, refer to
Multi-Point Limitations.
There are some things that should be considered when using the multi-point read functions. The multi-point
command can increase the speed of the data acquisition but if overused, it will need to make multiple multi-
point commands to read all the requested data. When this occurs, the overall performance of the driver will
be reduced. The key is to use the multi-point command wisely.
The driver will automatically group data from memory types like bit memory into 16 bit values. For example,
for the PC3 model, if P1-X1, P1-X3, P1-X4, P1-X6, P1-X9, P1-XA, P1-XB are marked as part of a multi-point
read using the '#', users would enter an address of #P1-X1, #P1-X3, #P1-X4, #P1-X6, #P1-X9, #P1-XA, #P1-
XB. These seven items would be placed into a single 16 bit value; therefore, users would use only one of the
128 16 bit values available in a single multi-point read command. The 7 items were grouped together
because the address of each bit fell within a single 16 bit word value of X memory. If 7 items like #P1-X1,#P1-
X20,#P1-X55,#P1-X77,#P1-X99,#P1-XAA,#P1-XBB are entered as part of a multi-point read, each bit in this
case would require an entire 16 bit value in the multi-point read command to receive the data. Plan the data
usage in the controller. If possible, make sure that the bits being read are grouped closely. This prudent
planning applies primarily to the bit memory types. Register memory requires a single 16 bit value (two 16
bit values in the case of DWords) for each register that is added to the multi-point read.
By using this information, users can plan the multi-point reads. The Toyopuc PC3/PC2 Ethernet Driver can
perform as many multi-point reads as are needed to acquire all the data that has been marked for multi-
point operation. Remember, however, that the driver will run slower when there are many read being run. To
determine how many multi-point read requests the Toyopuc Ethernet PC3PC2 driver is using to acquire all
currently defined multi-point data, use the special diagnostic tag "_DeviceMultiPointReads". For more
information on this tag, refer to Diagnostics.
The multi-point read operation can be combined with the normal data reads of the Toyopuc PC3/PC2
Ethernet Driver. For example, if a block of 50 D registers consecutively ordered is being read, it may be
more efficient to read the 50 D registers as part of a normal block read and save the space in the multi-point
read function for data that is spread more randomly throughout the PLC memory. Use the diagnostics tags
to help determine the most efficient way of acquiring the data for the application.
Multi-Point Limitations
For tags belonging to device models PC3 Device and PC10G Device, the maximum data requested for the
data types are as follows:
Boolean: 1024*
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