Totalizer overflow flags – Rockwell Automation 1771-QRD PULS FLOWMTR User Manual

Page 34

Advertising
background image

More on Overrange and Overflow

Chapter 5

5–2

Each time an input for one (or more) of the channels is greater than 10.0
kHz, the overrange flag for that channel is set; for example, if the input
frequency for channel 1 is greater than 10.0 kHz, bit #4 is set. (This is the
first bit of the overrange group.)

Acknowledge Word = 1010 = 0001

XXXX

XXX1

0000

Overrange, Channel 1

If the input frequency for any other channel is greater than 10.0 kHz, the
QRD sets the appropriate bit in the acknowledge code. It is possible for all
channels to be in an overrange condition; in such a case, the acknowledge
code would be:

Acknowledge Word = 10F0 = 0001

XXXX

1111

00000

All inputs are overrange (

u10.0 kHz)

The overflow flags work in the same manner as the overrange flags. As an
example, when totalizer #1 has reached its maximum (32,767), an
overflow flag (bit #8) is set in the acknowledge code. If the acknowledge
code is put in binary format, it looks like this:

Acknowledge Code = 1100 = 0001

XXX1

XXXX

0000

Overflow, Channel 1

Any or all of the four channels can overflow, and any or all of the overflow
flags can be reset using a Block Transfer Write command. If all of the
channels overflow, the acknowledge code will look like:

Acknowledge Code = 1F00 = 0001

1111

XXXX

0000

All inputs are overflowed (

u32,767)

Totalizer Overflow Flags

Advertising