The Philips high performance timer/counters PH 6652, PM
6654, PM 6652C and PM 6654C are fully programmable and
satisfy most frequency and time measurement requirements.
The four instruments look the same; the differences being
found in resolution, accuracy and measuring speed.
The PM 6652 and PM 6652C have a 10 MHz (100 ns) clock
frequency, whereas the extra high resolution PM 6654 and PM
6654C features a 500 MHz (2 ns) real time clock.
Thanks to their short measuring cycle times, the PM 6654 and
PM6654C are particularly well suited to high speed automatic
The 'C'-version, introduced in 1986, have new features added
to those of the original PM 6652 and PM 6654. A note is made
if a function described in this manual is not applicable to
the original PM 6652,-54.
All units are also available in blind panel versions.
Choice of crystal oscillators
The choice of crystal oscillators ranges from a standard
oscillator to the 5 x 10"“^/24 h oven stabilized oscillator
PM 9691. The high stability crystal oscillators are
available as options for later upgrading of the counters.
High measuring power
The two timer/counters feature 14 different measuring modes:
everything found in conventional counters, plus extra
functions such as: PHASE, (directly in degrees), RISE/FALL
TIME, DUTY FACTOR and VOLT. FREQUENCY and PERIOD
measurements are made very rapidly. The PM 6654 needs only
one second for a
9 digit resolution while the PM 6652, in the same time,
gives 7 digits. Both models perform measurements such as
burst frequency, multiple burst frequency average and
externally gated frequency measurements.
Trigger HOLD-OFF can be activated in frequency and period
modes. It inhibits stop triggering during an adjustable
hold-off time after start of the measurement, to avoid false
triggering due to noises or interference (e.g. relay bounce).
The mathematic facilities of scaling and/or offsetting the
measuring result extends the application possibilities. Some
- Vpp measurements can be converted to Vrms*
- Frequency readings from a transducer can be calibrated as RPM.
- Liters/s, gallons/min or m/s.
- Phase measurements can be converted from degrees to dians.
Time interval measuring accuracy
The PM 6654 with 2ns single shot resolution allows time
interval measurements with a very high accuracy and
resolution. Averaging a large number of measuring results in
time interval, pulse width or rise or fall time modes gives
a resolution of less than one picosecond with the PM 6654
and down to 10ps with the PM 6652.
The PM 6652/54 inputs feature 1ns rise times and 20mV
sensitivity over a -5V...+5V range. The counter can
simultaneously display the set trigger levels of both the A
and 8 channels. What appears on the display are the real
trigger points. Automatic hysteresis compensation enables
triggering at the set trigger level. Systematic trigger
errors are thus kept to an extremely low level.
The PM 6652/54 gives full control over defining start and
stop triggering. Arming and trigger hold-off enable
rejection of unwanted signals which would otherwise trigger
Simple programming of IEEE-488 bus performance
The PM 6652/6654 are fully programmable, including all
trigger controls. The optional interface card PM 9696 allows
bus operations at a low additional cost. The resolution and
measuring speed of the PM 6652/54 can be fully exploited by
using the hiqh speed dump mode, allowing up to 400...500
measurements per second. The IEEE 728/IEC-625-2 code and
format norms are fully implemented in these counters.
The PM 6652/6654 can write their own program messages. First
one finds the best control settings for a measurement.
Thereafter activate the BUS LEARN mode, and the counter
sends the status of all manually set controls to the
controller. This eliminates the risk of programming errors
and the need for debugging.
The eight ''stored panel programs" P1...P8 can also be
selected and created via the bus. This requires only one
message and greatly reduces the bus communication load.