Hardy HI 2151/30WC Single-Scale Controller - Manual (Page 118)

HI 2151/30WC MANUAL
7-20
• By connecting the remote functions print to the remote
functions ground.
Step 4. The output can be tri-stated if the OUTPUT DISABLE is
brought low. This is useful for multiple parallel outputs to be
connected to the same device. Once this input is brought high,
the latched data will be accessible again. The PRINT output is
normally low and goes high for 25 milliseconds. If the oppo-
site polarity (normally high, pulsed low) is desired, move
jumper from W1 to W2.
BCD Print Step 1. The weight select mode tells the output device which type of
data is present.
Step 2. The user selects which type of data is desired by toggling
"GNT" under the option BCD sub-menu.
Step 3. If all three types of data are requested, then all three will
appear on the output one after the other, 10 milliseconds apart.
Step 4. If "d" is selected, the output will follow the mode being dis-
played.
Output Disable Data output is discontinued if the OUTPUT DISABLE, pin 22 on the
PWA (pin 30 on the D-Subminiature connector), is low. The data pins
will be tri-stated even though print pulses will be sent.
Rate of Change
(ROC) (See Chapter 5 for Setup Procedures) The Rate of Change Option
is used to measure the rate at which a material enters or is dispensed
from a vessel over a given period of time.
To develop ROC data, a Register is used that is 21 entries in length.
New weight is input to the register at the rate of 1/20th of the Time
Base. The 1st register is subtracted from the 21st register. The 21st reg-
ister is one Time Base older than the 1st register. The results of this
subtraction are divided or multiplied, as necessary, to equal the appro-
priate measurement time for display, U-SEC, U-MIN, U-HOUR.
Example In this example the units of display are units per minute (U-Min) with a
Time Base of 10 seconds. Every ½ second new data is inserted into the
1st register and old data is shifted down one register. The 1st register is
subtracted from the 21st register and the results are multiplied by 6 so
the Time Base results of 10 seconds corresponds to Units per Minute.
100
102
104
106
108
110 21st - 1st (x) 6 = ROC
112