14
7.4.3.
Line resistance of RTD (thermoresistance) input
When the device has a thermoresistance input, the parameter
Ri
is used to define the line resistance
(the resistance of the copper cable connecting the sensor). This resistance must first be measured during installation.
The parameter tree for RTD input is:
Q
#
uSE
=
YES
oF
Fig. 7.4
Ri
PARAMETER
MINIMUM
MAXIMUM
UNIT
DEFAULT
Ri
)0
(9
)0
With line resistances over 3 Ω, the measurement range gets narrower with as many degrees Celsius
as the temperature corresponding to the surplus resistance!
7.4.4.
Programming the range of linear inputs
In case of a linear input, the parameter
Lo
is used to specify the value corresponding to the lowest input
current or voltage. Similarly,
hi
defines the value corresponding to the highest input current or voltage.
The parameter tree is:
Q
#
uSE
=
YES
Lo
Fig. 7.5
hi
Lower range limit of linear input
PARAMETER
MINIMUM
MAXIMUM
UNIT
DEFAULT
Lo
`999
9999
selected by operator
O
Upper range limit of linear input
PARAMETER
MINIMUM
MAXIMUM
UNIT
DEFAULT
hi
`999
9999
selected by operator
100
7.5.
Programming of first discrete input to switch the channels
externally
When the device has 1 discrete input, the parameter
s1
is used to enable the input and define its use.
parameter
s1
VALUE
COMMENT
YES
The input is used for external switching of the channels.
no
The input is not used (not used for external switching of the channels)
default value:
no