13
To calibrate the references connect a calibrator to
terminals 1 and 3. Select 'rEF' from the sub-menu
and press P which will result in a '0.004A' prompt
being displayed. Adjust the external current
calibrator to 4.000mA and again press P . The
indicator will display 'Ent' when the 4mA reference
has been updated and will then return to the
'.004A' prompt.
To re-calibrate the 20mA internal reference, press
the Up button which will cause the indicator to
display '.020A'. Adjust the external current
calibrator to 20.000mA and again press P . The
indicator will display 'Ent' when the 20mA
reference has been updated and will then return to
the '.020A' prompt. Two operations of the E button
will return the indicator to the main menu.
6.8 Function of the
P
push-button: C - - P
This parameter defines the function of the P push-
button when the indicator is in the display mode.
While the button is operated the indicator will
display the input current in milliamps, or the input
current as a percentage of the span.
To check or change the parameter select 'C - -P'
from the main menu and press P to reveal the
current setting. Pressing the Up or Down button
will toggle the setting between '4-20' the current
display and 'PC' the percentage display. When set
as required press E to return to the main menu.
Accuracy of the current display depends upon the
accuracy of the internal references which should
be periodically calibrated - see section 6.7.2
6.9 Security code: COdE
The calibration and conditioning of the instrument
may be protected by a four digit security code
which must be entered before access to the
programme menu is granted. New instruments
are programmed with the default security code
0000 which allows unrestricted access to all
programming functions.
To enter a new security code select 'COdE' from
the menu and press P which will cause the
indicator to display the current security code. Each
digit of the code can be changed using the Up and
Down push-buttons, and the P button to move to
the next digit. When the required code has been
entered press E to return to the main menu. The
revised security code will be activated when the
indicator is returned to the operating mode.
If the security code is lost, access to the
programmable functions can be obtained by
moving the internal security link to the override
position. The original security code can then be
viewed by selecting 'CodE' from the main menu
and pressing P.
To gain access to the security code link, remove
the instrument terminal block by gently pulling.
Unscrew the four corner screws securing the rear
panel an lift off the panel which will reveal the link
as shown in Fig 7.
Fig 7 Location of security code override link
6.10 Over and under-range
If the indicator display range is exceeded, the four
least significant digits will be blanked. Under-
range is indicated by '-1' and over-range by '1'.
Under and over-range are also indicated if the
input current falls below approximately 3.5mA or
rises above approximately 21mA.
If the input current falls below 3mA the instrument
initialisation sequence is performed as described
in section 2.
