Yokogawa EJX440A - Manual (Page 12)

IM 01C25T03-01E 3-4
3. OPERATION
3.2 Setting Parameters Using the
BT200
3.2.1 Parameter Usage and Selection
Before setting a parameter, please see the following
table for a summary of how and when each parameter
is used.
IMPORTANT
After setting and sending data with the BT200,
wait 30 seconds before turning off the transmit-
ter. If it is turned off too soon, the settings will
not be stored in the transmitter.
Table 3.2.1 Parameter Usage and Selection
Setup item Description
Tag No. setup ᭤ P.3-6 Sets the Tag No. (using 16 alphanumeric characters).
Calibration range setup
᭤ P.3-6
Sets the calibration range for 4 to 20 mA DC. Sets the following items: range unit, input value
at 4 mA DC (LRV), input value at 20 mA DC (URV), and decimal point position.
Note: LRV and URV 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.3-7
Adjusts the output response speed for 4 to 20 mA DC at amplifier.
Can be set from 0.50 to 100.00 s. (from 0.00 to 100.00 s with quick response mode on)
Output and integral indicator display
mode setup
᭤ P.3-8
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.3-8
Used mainly to stabilize output near 0% if the output signal is 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 display function
᭤ P.3-9
Available from the following 5 types of integral indicator scale ranges and units:
input pressure, % of range, user set scale, input static pressure, % of static pressure
range, and alternating among any four of the above.
Configure the following when using the user set scale;
user set scale setting, unit (BT200 only), display value at 4 mA DC (LRV), and display
value at 20 mA DC (URV).
Note: LRV and URV can be specified with range value specifications up to 5
digits (excluding any decimal point) within the range of –32000 to 32000.
T0305.EPS
Unit setup for displayed temperature
᭤ P.3-11
Sets the unit for temperatures displayed on the BT200.
Static pressure setup
᭤ P.3-11
Sets the parameters concerned with static pressure such as unit, calibration range, upper
and lower range values, decimal point position, damping time constant.
Operation mode (normal/reverse
signal) setup
᭤ P.3-11
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.
CPU Failure burnout direction and
hardware write protect
᭤ P.3-11
Displays the status of 4 to 20 mA DC output when a CPU fails. The direction is selectable
by the hardware switch on the amplifier. It also physically prevents parameter access.
Software write protect ᭤ P.3-12 Configured data can be protected by setting a password.
Output status setup when a hardware
error occurs
᭤ P.3-13
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. Either the last held,
high limit, or low limit values status, can be selected.
Range change (while applying
actual inputs)
᭤ P.3-13
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.
Sensor trim ᭤ P.3-14 Adjusts zero point and span of the sensor.
Test output (fixed current output)
setup
᭤ P.3-17
Used for loop checks.
Output can be set freely from –2.50% to 110.00% in 0.01% steps.
Signal characterizer ᭤ P.3-17 Used to compensate the output for the non-linear application.
User memo fields
᭤ P.3-21
Allows user to enter up to 3 items, each containing any combination of up to 16
alphanumeric characters.
Process alarm ᭤ P.3-18 Used for alarm generation on the integral indicator.
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.3-11
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.3-13
Status output ᭤ P.3-18 Outputs an on/off digital signal based on the settings of process alarm.
Capillary fill fluid density
compensation
᭤ P.3-20
Compensates the zero shift by the ambient temperature effect on the capillary tubes.