User Manual

Publication 1746-UM010B-EN-P - April 2001

5-8 Control and Autotune a Loop

Using the Output Image

Table

The output image table contains 16 words as shown in Table

5.Cbelow. You must enter a 16–bit signed integer value for the run

temperature setpoint and manual output. If you are using the example

code from the manual you will not manipulate the output image table

directly. You will manipulate the output image buffer N10:180-195.

• For a run temperature setpoint, the implied decimal point is 1

place from the right (causing the resolution to be 0.1). For

example, if you want a value of 499.9, enter 04999.

• For the manual output, the implied decimal point is 2 places

from the right (causing the resolution to be 0.01). For example,

if you want a value of 49.99%, enter 04999.

Note: Refer to Download and Upload Settings on page 9-3 for

download command bits.

Table 5.C Operating Commands to Loops 1-4

Loops 1-4

Word #

Set a bit or enter a value

12 3 4 bit to Configure Bit Select or Range1514131211109876543210

0 1 2 3 0 loop control Disable=0; Enable=1

1 Auto/manual Manual =0; Auto =1

2 Setpoint select

Standby=0

(2)

; Run=1

(3)

3 Autotune enable Disable=0; Enable=1 X

PID integral reset

(1)

Accume = 0;Reset =1 X

5 Ramp enable Disable = 0;Enable =1 X

6 Ramp hold Hold =0; Don’t hold =1 X

7-15 Reserved

4 5 6 7 0-15 Run temp setpoint -3276.7 thru 3276.7

8 9 10 11 0-15 Manual Output -100.00 thru +100.00%

(1)

Requires a 0-to-1 transition for each reset.

(2)

For loops 1-4 standby setpoint is stored in N10:5, 30, 55, 80 respectively.

(3)

Entered below