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Instruction Manual A70 Version 6 19th April 2004
BEKA associates Ltd, Old Charlton Road, Hitchin, Hertfordshire. SG5 2DA. UK. Tel: +44 (0) 1462 438301
8.5.7) “rEF” – Setting Internal References
.
Do NOT enter this program parameter unless you have an accurate and
traceable signal source to hand.
The internal references are used by the meter to calculate readings for the internal
calibrator (“cAL”), the units/percentage function (“U--P”) and the analogue output option. The internal references are protected
against accidental erasure by the request for the code “sure”. The internal input references (“IP”) are set by sampling an
accurate external signal source at “zero” and “span” levels as shown in the diagram below. E.g. if the signal input range was
1-5V, 1V should be sampled at the “zero” and 5V at the “span”.
The 4-20mA analogue output (if fitted) can be adjusted (to a minimum 3.8mA and maximum 22mA) using the up or down
buttons within the “SEt” options.
8.5.8) “Iout” – 4-20mA Analogue Output. (If
fitted)
This parameter allows the 4-20mA analogue output to
be programmed to correspond to any part of the display
range. E.g. the display range could be 0-500 Litres, and the 4-
20mA re-transmission could be from 100-150 Litres. To set
the actual mA output levels, see section 8.5.7).
8.5.9) “F.Pan” - Front Panel Controls,
Password and Pushbutton Disable (anti-
tamper function).
The front panel controls referred to here allow the operator to
set a security access password (or change an existing one)
and to switch on the anti-tamper feature - “bttn”. If “bttn” is set
to “on”, then the buttons are enabled, if set to “off” then the
buttons are disabled (to re-enable see section 8.7).
The security password that is entered within the “code”
parameter will be the password required to gain access to the
programming mode from normal display mode. If “0000” (four
zeroes) is used, then no password is needed to gain access
to programming mode.
If a password has been forgotten,
then the emergency access code “FPAc” (“Forgotten
Panel Access Code”) can be used to gain access
. If FPAc
is entered as a code then the present password will be
shown. If desired, a new password can be entered.
8.5.10) “ALr1” & “ALr2” –Alarm Setpoint
Programming (If Fitted).
Section 8.6) outlines the parameters that can be set.
8.6)The Alarm Parameters
.
Alarms 1 & 2 have the
same set-up parameters, but operate separately.
Each can be set as a high or low alarm. See sub-
menu programme flowchart of the following page.
8.6.1) “EnbL” – Enable
. This gives a quick way of
switching the alarm on or off without having to
change all the other alarm parameters.
NOTE: If the
alarms are not enabled, the alarm relays will stay
in the position determined by the “nE” (normally
energized) parameter.
8.6.2) “hStr” – Hysteresis
Hysteresis is set in
absolute units not percentage. This function is useful
to stop alarm “chatter” as shown in the diagram
below.