Rockwell Automation 1336T ControlNet Frn1.02 Rev 1.5 - Manual (Page 40)

3–4 Using Scheduled Discrete Data Transfer
Publication 1336 FORCE–5.18 ––March, 1999
Information from the 1336 FORCE consists of parameter 56, Logic
Status LOW, and parameter 146, Velocity Feedback. Based on the
links shown, the 16-bit input word for group 0, rack 2 in the PLC
controller is a 16-bit logic status word. The description for
parameter 56 defines the bits in this 16-bit word. In addition, the
16-bit input for group 1, rack 2 in the PLC is a 16-bit signed integer
whose value corresponds to the allowable values in drive units for
parameter 146.
Scaling
If the PLC is to manipulate the data transferred between the 1336
FORCE and the PLC in units other than drive units, the data must be
appropriately scaled when it is transferred to a drive parameter. You
can do the scaling either at the PLC or by using drive function
blocks. The scaled information must be based on drive unit
definitions for parameters in the 1336 FORCE.
Parameter 101, Velocity Reference 1 HI, shown in the previous
figure, is in drive units, where 4096 is defined as base speed. If the
PLC controller program is written in terms of feet-per-minute (fpm),
then you need to convert fpm to drive units before sending it to
parameter 101.
Discrete I/O Program Example
A PLC controller program is shown on the next page. You could use
this example to control the 1336 FORCE. Based on the
configuration shown in the previous figure, the PLC program
transfers information to parameters 367 and 101 in the 1336 FORCE.
Logic bits in File B3 of the PLC are used to set the drive logic
control bits, and integer file N10 word 01 is used to store the drive
speed reference.
To control the logic operation of the drive, the PLC program must
control the bits in the output image table that correspond to the
desired operation. Because parameter 322 in the previous figure has
been linked to parameter 367 and parameter 322 is associated with
group 0 in the output image table, the PLC program is controlling
bits in word 0:20.