JPSM
EM-1689 Rev.5
P. 3 / 8
FUNCTIONS & FEATURES
• Adding two pulse inputs (counting number of pulses) and converting the pulse rate into convenient engineering unit for display
on a totalizing counter or meter
• Wide frequency range up to 100 kHz (5
µ
sec. minimum)
• Monitor LED is provided for checking input pulse
• Accepting a wide variety of input: 0.5 – 50V at the input terminals
• Parameters can be programmed via the Programming Unit, PU-2x.
• Sampling time can be changed.
• Additional functions of the Programming Unit: monitoring input values and parameters
• Maximum output frequency limit
• Duty cycle ratio of the output pulses: 50%
EXPLANATIONS OF TERMS & FUNCTIONS
■
BASIC OPERATION
After the power is turned on, the JPSM accesses and checks the data stored in its non-volatile memory. When there is no
abnormality, it starts measuring.
After one cycle of sampling time is over, it calculates the measured results (total number of input pulses and pulse rate) to get
number of output pulses and frequency, and provides these pulses before the next sampling is complete.
When the calculated output frequency is higher than the preset limit, the unit stores the surplus number of pulses in the memory
and outputs them when the frequency become lower.
When the input cycle (inverse value of input frequency: input 1) is longer than the preset cutout time, the unit enters the cutout
mode. However, because the cutout function is affected only by the input frequency, not pulses, the cutout mode does not affect
the function of the JPSM. The input pulses are not cut out.
When the input pulses are continuously fed, the output waveform is mostly uniform within each sampling cycle. However, when
the input pulses are stopped in a particular timing, the last pulse string may be provided in low frequency, and so may be the
first pulse string.
Remark: The cutout time is set so that the transmitter forcibly discontinues a sampling cycle and outputs 0 Hz.
■
SCALING FACTOR, INPUT SPAN FREQUENCY & OUTPUT SPAN FREQUENCY
The scaling factor, rate of number of output pulses divided by number of input pulses, are determined by two parameters: input
span frequency and output span frequency.
Although there are also input zero frequency and output zero frequency, they are fixed to zero (0) Hz.
These span frequencies are only used to determine the rate, therefore they do not limit actual input / output frequencies. For
example, if you set the input span frequency to 1 Hz and the output span frequency to 2 Hz, you can input 1000 Hz and the number
of output pulses are twice as much as the input, approximately 2 kHz.
■
OPERATION MODE AND MAINTENANCE SWITCH
There are two operation modes: MONITOR mode and PROGRAM mode.
When the power supply is turned on, the unit starts up in MONITOR mode. However, you can switch from one mode to another
by operating the Programming Unit.
In MONITOR mode (Maintenance Switch = 0), the unit is in normal operation: repeating measuring, calculating and renewing
the output signal. In this status, the status indicator LED is blinking in constant intervals of approx. 3 Hz (ON : OFF = 1 : 1).
You can monitor input frequency, input %, output % and operating status, various parameters, etc. on the Programming Unit.
The PROGRAM mode (Maintenance Switch = 1) is used when you change various parameters concerning measuring, calculation
and output. In this status, the status indicator LED is blinking in constant intervals of approx. 1.5 Hz (ON : OFF = 1 : 1). In
the transition period from MONITOR to PROGRAM mode, the LED blinks approx. in 1.5 Hz but in different intervals (ON : OFF
= 1 : 3), which indicates that the unit is still processing the last cycle of measuring.
In PROGRAM mode, the unit stops measuring and renewing the output signal. The output is held, but you can output a specific
value for simulation and testing.
When all the program change is over, be sure to return the transmitter to MONITOR mode. The modification will be lost if you
turn off power supply to the transmitter without doing this.
MONITOR MODE
Measuring Processing
Monitor. Parameters
Available
Monitor. Measuring
Value Available
PROGRAM MODE
Measuring Stopped
Changing Parameters
Available
Output Simulation
Available
Maintenance Switch = 1
Maintenance Switch = 0
Parameters Saved
in the Nonvolatile Memory.
Power
Turned ON
