Rockwell Automation 1771-QC , D17716.5.25 SER/B SERVO POS - Manual (Page 164)

Chapter 8
8Ć3
Figure 8.2 shows the formats of block transfer instructions for
Mini-PLC-2/15 and PLC-2/30 controllers. For each block transfer
instruction for these PCs, you must specify:
Data Address - The address of a word in the timer/counter accumulated
value area of the data table. This word contains the 1771-M3 controller
module location address, in BCD format.
For bidirectional block transfer, there must be two data address words
in consecutive data table locations: one for the write transfer, and one
for the read transfer. These words contain the same module location
address.
Module Address - A 3-digit number of the form RGS, where R is the
rack number, G is the module group number, and S is the slot number
(0 or 1). This value is stored in the data address word.
Block Length - Specifies the number of words to be transferred. For
the servo positioning assembly, program 00 as the block length. This is
the default value. When the PC executes the block transfer
instructions, the 1771-M3 controller automatically sends or requests the
correct number of words.
File - The data table address of the first word in the block to be
transferred. For read transfer, this address is constant. For the write
transfer, your program changes the address according to the address
pointer in the status block. Note that the address of the first word in the
block to be transferred is stored in a data table word 100
8 above the
data address.
Figure 8.2 also shows enable (EN) and done (DN) outputs for each block
transfer instructions. The PC automatically enters addresses for these
output according to the module location address you enter. These
addresses specify bits of the input and output image table bytes that
correspond to the 1771-M3 controller location.
PLCĆ2 Family Block Transfer
Instructions