Table of Contents
Advertisement
12-8 Chapter 12
GSE Scale Systems
F
O
REQUENCY
UTPUT
This function allows the 660 to output a digital signal with variable
frequency and/or duty cycle. This capability may be used along with some
appropriate external devices to control the speed of a conveyor motor, the
amount a valve is opened or closed, or any other function normally
requiring an analog signal. However, due to the nature of digital data, the
output signal is less susceptible to electrical noise than an analog signal.
The setup parameters that pertain to the 'FqOut' selection are:
P852: "FNam": Allows a name to be assigned to I/O parameter 50 which
is used to specify the output frequency for this function.
P853: "DNam": Allows a name to be assigned to I/O parameter 51 which
is used to specify the duty cycle of the output frequency for this function.
P857: "CSrc": Specifies which clock will be used to generate the signal
specified for this channel. The effects of the two alternatives are shown in
Table 12-2.
Table 12-2: Frequency Output Based on Clock Source
Clock Frequency
Clock Period
Minimum
Generated
Frequency with
Full Duty Cycle
Range
Absolute Minimum
Generated
Frequency (Duty
Cycle = 50%)
Absolute
Maximum
Generated
Frequency
(allows 50% duty
cycle only)
Maximum
Recommended
Generated
Frequency
(allows 1% duty
cycle resolution)
The general restrictions listed in Table 12-2 can be attributed to the
following facts:
1. The period and high time of the generated signal can only be a
multiple of the period of the selected clock.
: (F
UNCTION
Clock
Clock
A
B
65,536
524,28
Hz
8 Hz
15.26
1.91
µs
µs
2 Hz
16 Hz
1 Hz
8 Hz
32768
262,14
Hz
4 Hz
655 Hz
5242
Hz
1)
Hide quick links:
Advertisement
Table of Contents
