Rockwell Automation 1746-NO8V SLC 500 8-Point Analog Output Module/ User Manual User Manual
Page 41
Publication 1746-UM026A-EN-P - September 2003
Configuring the Module 4-17
EXAMPLE 4: Set Ramping/Rate Limit Values
Suppose you have a valve connected to Channel 4 with a 4 to 20
mA operating range and you want to use PID format. You would
use the following bit settings for the Channel 4 configuration word:
Suppose, also, that you would like the output to change no more
than 1.5 mA per second.
Since the ramping value is expressed as 0.1 mA per second, your
value would be 1.5 ÷ 0.1 = 15. You would enter the following for
Channel 4 data parameter 1. Note, data parameter 2 is not used for
ramping:
O:e.20
Value = 15 decimal
(Channel 4 Data Parameter 1)
(1.5mA per second)
Now set the bits in the Channel 4 configuration word:
Monitor bit 3 of Channel 4 Input Status Word 2 (I:e.12). When this
bit is a 1 (Ramping/ Rate Limiting value set), then set the Channel 4
configuration back to its original value:
Ramping is now active.
Set Preset Fault Value
This feature allows you to define a preset output value for a fault
condition. The value for a channel is configured by placing the
desired value into Output Data Parameter Word 1 for the desired
channel and then setting the Output Configuration Word for the
channel to set the Preset Fault Value. The module will revert to this
value when a fault condition occurs, if Preset Output on Fault is set.
See Fault Options (configuration bits 12 and 13) on page 4-10 for
information about fault conditions.
Address
15
Channel 4 Configuration Word
0
O:e.12
0
0
0
0
0
0
0
0
0
0
1
0
0
0
1
1
Address
15
Channel 4 Configuration Word
0
O:e.12
0
0
0
0
1
0
0
1
0
0
1
0
0
0
1
1
Address
15
Channel 4 Configuration Word
0
O:e.12
0
0
0
0
0
0
0
0
0
0
1
0
0
0
1
1