Yokogawa EJX115A - Manual (Page 12)

<3. Operation>
3-4
IM 01C25T03-01E
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.
Table 3.1 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.
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.
Unit setup for displayed
temperature ►P.3-11
Sets the unit for temperatures displayed on the BT200.
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.
Impulse line connection orientation
(higher pressure on right/left side)
setup ►P.3-11
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.
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.
Bi-directional flow measurement
►P.3-13
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.
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 the transmitter 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.
Process alarm ►P.3-18 Used for alarm generation on the integral indicator.
Status output ►P.3-18 Outputs an on/off digital signal based on the settings of process alarm.
Capillary fill fluid density
compensation ►P.3-19
Compensates the zero shift by the ambient temperature effect on the capillary tubes.
User memo fields
►P.3-20
Allows user to enter up to 3 items, each containing any combination of up to 16 alphanumeric
characters.
IMPORTANT
After setting and sending data with the
BT200, wait 30 seconds before turning off the
transmitter. If it is turned off too soon, the settings
will not be stored in the transmitter.