Rockwell Automation 20-COMM-D DeviceNet Adapter Series B FRN 2.xxx - Manual (Page 157)

Using Explicit Messaging 6-29
20-COMM-D DeviceNet Adapter User Manual
Publication 20COMM-UM002G-EN-P
SLC 500 Controller Example Read Single Response Data
In this message example, we use the data table address in Figure 6.31 to
store the response value (0.13 amps) that was read from drive parameter 003
- [Output Current].
In this example, Output Current is a 32-bit parameter. For PowerFlex 700S
drives, Output Current is a floating point number. To manipulate REAL data
into a proper Float tag, see the ‘Communications’ section in Chapter 1 of
the PowerFlex 700S AC Drives Phase II Control Reference Manual,
publication PFLEX-RM003.
Figure 6.31 Example Read Single Response Data File
SLC 500 Controller Example Ladder Logic Program to Write a Single Parameter
Using Read/Write Parameter Service
A Write Parameter message is used to write to a single parameter. This
write message example writes a value to parameter 140 - [Accel Time 1] in
a PowerFlex 7-Class drive.
Figure 6.32 Example Ladder Logic to Write a Single Parameter
Important: If the explicit message single write must be written
continuously, use the Generic Set Attribute Single service and
attribute A (10 decimal; see
page 6-33 ). This writes to RAM—
not NVS (EEPROM) memory. This example single write
message using Class code F writes to NVS. Over time,
continuous writes will exceed the EEPROM life cycle and
cause the drive to malfunction.