Yokogawa EJA118 - Manual (Page 35)

IM 1C22H1-01E 7-6
7. BRAIN TERMINAL BT200 OPERATION
7.3.2 Parameter Usage and Selection
Before describing the procedure for setting parameters,
we present the following table showing how the
parameters are used and in what case.
IMPORTANT
If the transmitter is turned off within 30 seconds
after parameters have been set, the set data will
not be stored and the terminal returns to previ-
ous settings.
Table 7.3.1 Parameter Usage and Selection
Setup Item Description
Tag No. setup
᭤ P.7-7
Sets the Tag No. (using 16 alphanumeric characters).
Note: Up to 8 alphanumerics (upper case letters) can be used in the BT100.
Calibration range setup
᭤ P.7-7
Sets the calibration range for 4 to 20 mA DC. Sets three data items: range unit, input value
at 4 mA DC (LRV), and input value at 20 mA DC (HRV).
Note: LRV and HRV can be specified with range value specifications up to 5 digits
(excluding any decimal point) within the range of –32000 to 32000.
Damping time constant setup
᭤ P.7-8
Adjusts the output response speed for 4 to 20 mA DC.
Can be set in 9 increments from 0.2 to 64 s.
Output and integral indicator display
mode setup
᭤ P.7-9
Sets modes for output signal and integral indicator to “Linear mode”
(proportional to input differential pressure) or to “Square root mode” (proportional to flow).
Output signal low cut mode setup
᭤ P.7-9
Used mainly to stabilize output near 0% if output signal is the square root mode.
Two modes are available: forcing output to 0% for input below a specific value, or changing
to proportional output for input below a specific value.
Integral indicator scale range and
unit setup
᭤ P.7-10
Sets the following 5 types of integral indicator scale ranges and units:
% scale indicator, user set scale indicator, alternate indication of user set scale
and % scale, input pressure display, alternate indication of input pressure and % scale
When using the user set scale, 4 types of data can be set:
user set scale setting, unit (BT200 only), display value at 4 mA DC (LRV), and display
value at 20 mA DC (HRV).
Note: LRV and HRV can be specified with range value specifications up to 5
digits (excluding any decimal point) within the range of –19999 to 19999.
T0707.EPS
Unit setup for displayed temperature
᭤ P.7-11
Sets a unit for temperatures displayed on the BT200.
Unit setup for displayed static
pressure
᭤ P.7-11
Sets a unit for static pressure displayed on the BT200.
Operation mode (normal/reverse
signal) setup
᭤ P.7-12
Reverses the direction for 4 to 20 mA DC output relative to input.
Reverse mode is used for applications in which safety requires that output be
driven toward 20 mA if input is lost.
Output status display/setup when
a CPU failure
᭤ P.7-12
Displays the status of 4 to 20 mA DC output when a CPU failure. The parameter
of the standard unit is fixed to the high limit value.
Output status setup when a hardware
error occurs
᭤ P.7-12
Sets the status of the 4 to 20 mA DC output when an abnormal status is detected
with the capsule or the amplifier as the result of self-diagnosis. One of the
following statuses; last held, high limit, and low limit values, can be selected.
Range change (while applying
actual inputs)
᭤ P.7-13
Range for 4 to 20 mA DC signal is set with actual input applied. Sets 20 mA DC output
precisely with respect to user’s reference instrument output. Note that DPharp is calibrated
with high accuracy before shipment, so span should be set using the normal range setup.
Zero point adjustment
᭤ P.7-14
Adjusts zero point. This can be done either using the external zero-adjustment screw on
the transmitteror using the BT200.
Test output (fixed current output)
setup
᭤ P.7-15
Used for loop checks.
Output can be set freely from –5% to 110% in 1% steps.
User memo fields
᭤ P.7-15
Allows user to enter up to 5 items of any desired text in up to 8 uppercase
alphanumeric characters per item.
Used where installation conditions make it imperative to connect high pressure side
impulse line to low pressure side of transmitter. Reversal of orientation should be dealt with
by reversing impulse line wherever possible. Use this function only where there is no
alternative. Impulse line connection orientation
(higher pressure on right/left side)
setup
᭤ P.7-12
Used to measure bi-directional flows.
Output at zero flow is 12 mA DC, with output range equally divided between forward and
reverse flow.
Can be used with square root mode. Bi-directional flow measurement
᭤ P.7-13