Page 4
2.3.7
Serial Communications
There are three serial communication options – Ethernet, USB and RS232. The Ethernet option will have a standard
RJ45 connector, the USB option will have a type B female connector, and the RS232 option will have a male DB9
connector on the rear panel. The connections of the Ethernet and USB are generic. For information on setting up the
Ethernet Interface refer to Appendix D. The connection of the RS232 DB9 is shown here:
Pin
Description
Direction
2
Receive data
In
3
Transmit Data
Out
5
Common (GND)
7
Request to Send RTS Out
8
Clear to Send CTS
In
All other pins are not used. Communications are at the preset Baud Rate, 8 bits, No Parity and 1 stop bit.
3.0
FRONT PANEL
for a photo of the front panel.
The front panel of the instrument has 5 push buttons, five 0.56‖ 7 segment light emitting displays, and six single light emitting
diodes (LED’s), marked LIM 1, LIM 2, GATE, MIN, MAX and RPM. Some of these LED’s may not be visible; it depends on
the mode the unit is in.
3.1
Status LED’s
3.1.1
LIM 1 and LIM 2 (Alarm) LED’s
The
LIM 1
and
LIM 2
(Alarm) LED’s indicate the status of the limits, particularly of the alarm output relay. When an
alarm trips, the corresponding LED blinks at a rate around 1 flash per second. When the alarm resets, the LED goes
out. These LED’s also go on continuously to indicate when and which limit is being set or adjusted. If the LED’s are
on continuously, the value on the display is a set point value, not the input value.
3.1.2
GATE LED
The
GATE
LED is an indication of the instrument’s input trigger signal from a sensor. It is triggered on by the falling
edge of an input pulse, and goes off about 150 milliseconds later (unless there is another input pulse). It is more useful
at slow speeds, as it appears to be on continuously at higher inputs. It gives an indication that a valid input trigger
signal is present.
3.1.3
MAX and MIN LEDS
The
MAX
and
MIN
LED’s indicate to the user that a maximum or a minimum is being displayed. If either one of
these LED’s is on, the display is a stored value, not the input value.
3.1.4
RPM LED
The
RPM
LED indicates that the RPM Mode (frequency x 60) has been selected, which can only be used when the
input is
one pulse per revolution
. The
RPM
LED is off in all other modes. In the
Scale Mode
the read outs may be in
RPM, but the
RPM
LED will be off.
NOTE:
For applications where there is more than one pulse per revolution, the
Scale Mode
must be used.
3.2
Push Buttons
The five push buttons on the front panel have multiple functions. The following sections cover the function of the buttons
under normal operating conditions.
3.2.1
SET BUTTON
The
SET
button enters the Menu and allows the user to view the current settings in the unit. Refer to
3.2.2
RESET BUTTON
The
RESET
button, when pressed, resets the Alarms, assuming they have tripped. It is the only way to reset a latching
alarm other than via the serial interface.
NOTE:
If an alarm set point is exceeded when the reset button is pressed, the alarm will immediately trip again on
the next data acquisition cycle.
If the user holds the
RECALL
button and then presses the
RESET
button, the minimum and maximum values (and the
TOTAL if the unit is in the Totalizing mode) are reset.
In the Single Event Capture (SECAP) Mode, pressing the
RESET
button signals the instrument to take a reading at the
next trigger as well as its normal functions.
When in the Menu, the
RESET
button reverts back one level without saving any changes (
) or exits the Menu
(
). However, when entering data values in the menu such as scale factor, set point, Ethernet settings or passcode,
