Ramp/Soak Profile Monitoring; Ramp/Soak Programming Errors; Testing Your Ramp/Soak Profile - Automation Direct DL05 User Manual

Chapter 8: PID Loop Operation
The normal state for the ramp/soak control bits is all zeros. Ladder logic must set only one
1
control bit at a time.
• Start – a 0 to 1 transition will start the ramp soak profile. The CPU must be in Run Mode, and the
2
loop can be in Manual or Auto Mode. If the profile is not interrupted by a Hold or Jog command,
it finishes normally.
3
• Hold – a 0 to 1 transition will stop the ramp/soak profile in its current state, and the SP value will
be frozen.
• Resume – a 0 to 1 transition cause the ramp/soak generator to resume operation if it is in the hold
4
state. The SP values will resume from their previous value.
• Jog – a 0 to 1 transition will cause the ramp/soak generator to truncate the current segment (step),
5
and go to the next segment.

Ramp/Soak Profile Monitoring

6
You can monitor the Ramp/Soak profile status using other bits
in the Ramp/Soak Settings V+33 word, shown to the right.
7
• R/S Profile Complete – =1 when the last programmed step is
done.
8
• Soak PV Deviation – =1 when the error (SP–PV) exceeds the
specified deviation in the R/S table.
• R/S Profile in Hold – =1 when the profile was active but is now
9
in hold. Ramp/Soak Settings V+33
The number of the current step is available in the upper 8 bits
10
of the Ramp/Soak Settings V+33 word. The bits represent a 2-
digit hex number, ranging from 1 to 10. Ladder logic can
11 monitor these to synchronize other parts of the program with
the ramp/soak profile. Load this word to the accumulator and
shift right 8 bits, and you have the step number.
12

Ramp/Soak Programming Errors

The starting address for the ramp/soak table must be a valid
13
location. If the address points outside the range of user V-
memory, one of the bits to the right will turn on when the
14
ramp/soak generator is started. We recommend using
DirectSOFT 5 to configure the ramp/soak table. It
automatically range checks the addresses for you.
A

Testing Your Ramp/Soak Profile

B
It's a good idea to test your ramp/soak profile before using it to control the process. This is
easy to do, because the ramp/soak generator will run even when the loop is in Manual Mode.
Using DirectSOFT 5's PID View will be a real time-saver, because it will draw the profile on-
C
screen for you. Be sure to set the trending timebase slow enough to display completed ramp-
soak segment pairs in the waveform window.
D
8–60
DL05 Micro PLC User Manual, 6th Edition, Rev. A
Ramp/Soak Settings V+33
Bit 15 14 13 12 11 10 9 8 7 6 5 4
R/S Profile in Hold
Soak PV Deviation
R/S Profile Complete
Ramp/Soak Settings V+33
Bit 15 14 13 12 11 10 9 8 7 6 5 4
Current Profile Step, 2–digit hex
Value = 01 to 10 hex,
or 1 to 16 decimal
Ramp/Soak Table Error V+35
Bit 15 14 13 12 11 10 9 8 7 6 5 4
Starting Address set in
reserved system V-memory
Starting Address set out of
V-memory upper range
Starting Address set out
of V-memory lower range
3 2 1 0
3 2 1 0
3 2 1 0