Rockwell Automation 1395 ControlNet Communication Board - Manual (Page 24)

3–10 Configuration & PLC Interfacing
Publication 1395–5.37– March, 1999
is used to store the speed reference for the Drive. The MOV block in
rung 6 of Figure 3.5 transfers the 16 bit word of N10:01 to word 2 of the
output image table. Because word 2 of the output image table is sent to
parameter 301, which in turn is linked to parameter 154 (Figure 3.4), the
16 bit word N10:01 is the speed reference input to the Drive param. 154.
Information transferred back to the PLC Controller from the Drive is
handled much as it was in the previous example, with the exception that
data is transferred from the input image table of the PLC Controller to the
working data files in the PLC Controller program. Again, note that bit
coded words such as Logic Status (parm 100), are bit numbered in Octal
in the PLC Controller, while the Drive is in Decimal.
Command Set The CNA board supports a limited set of PCCC commands by emulating
a section of PLC-5 memory. The memory area emulated determines what
specific request and or action the CNA board will take. Below is a list of
the supported commands:
NOTE: A maximum of 5 parameters can be obtained with each
transaction.
Who Active – The node address of the CNA board (as defined by it’s DIP
switch settings) will be displayed on the “Who Active” screen of the PLC
software. It will read “1395 DRV” next to the selected station.
PLC 5 Typed Read (N10:0-999) – Memory area N10:0-999 translates
into a read parameter value(s) from the Drive. Any attempts to read
outside of this range will result in an error response. The values 0 through
999 are interpreted by the Drive as parameter numbers. For example, to
read the value of parameter 633 the MSG instruction would request
N10:633 with a size of one element. A size of 5 will read to parameters
633 through 637.
PLC 5 Typed Write (N10:500-999) – Memory area N10:500-999
translates into a write parameter value(s) to the Drive. Any attempts to
write outside of this range will result in an error response. The values 500
through 999 are interpreted by the Drive as parameter numbers. For
example, to write a value to Preset Speed 1 (parameter 633) the MSG
instruction would specify N10:633 with a size of one element. A size of 5
will write to parameters 633 through 637.
PLC Typed Read (N20:499-999) – This request reads the status of the
previous parameter writes (N20:500-999). If a Typed Read is specified
with an PLC address of N20:499, the write status of all parameters from
the last TYPED WRITE request (N10: xxx-xxx) will be OR’ed together.
If one error has occurred during the last write operation, this address will
contain the parameter number where the error occurred. If multiple errors
occurred the value will be 0FFFF (hex), and the PLC Controller can
request a Typed Read of N20:500-999 to determine which parameters
have had errors.