Yokogawa AXFA14G/C - Manual (Page 50)

IM 01E20C02-01E 6-21
6. PARAMETER DESCRIPTION
[F21: DIO Function] Setting of the function for the DIO status input/output terminal
This parameter sets the function for the DIO (status input/output) terminal.
Setting
No Function No function As no function is set, there is no input and output.
Warning Output Output upon warning
Total Switch(O) Totalization switch output
Refer to Alarms (Section 6.5).
Alarm Output Output upon alarm
H/L Alarm(O) H/L alarm output
HH/LL Alarm(O) HH/LL alarm output
Fwd/Rev Rngs(O) Forward/reverse flow rate measurement
Auto 2 Rngs(O) Automatic 2 ranges switching
Auto 3 Rngs(O) Automatic 3 ranges switchings (Note 1)
Auto 4 Rngs(O)
Ext 2 Answer(O)
Ext Ttl Set(I)
Ext R Ttl Set(I)
Automatic 4 ranges switchings (Note 1)
Answerback: 2 ranges switching via
external status input
Ext Auto Zero(I)
Automatic zero adjustment via
external status input
Forward totalization preset via
external status input
Ext 2 Ranges(I)
2 ranges switching via external status
input
Reverse totalization preset via
external status input
When flow is in the reverse direction, switching to the reverse
range is carried out automatically, measurement is performed,
and status output is carried out.
When range switching is carried out in response to external
status input, status output is performed in the form of an
answerback to indicate the range currently being used.
0% Signal Lock(I)
0% signal lock via external status
input
Description Function
T0623.EPS
Note 1: When these functions are selected, two terminals become necessary for status output, the DO and DIO
terminals which cannot be used for other functions.
Automatic zero adjustment is carried out in response to
external status input. For more details regarding automatic
zero adjustment, refer to Chapter 9: Operation.
This function allows the switching of 2 ranges in response
to status input for a single direction only.
This function ensures that when the instantaneous flow
rate exceeds 100% of the range, transition to the next
range is carried out automatically. Status output is carried
out upon range switching.
Based on the external status input, the instantaneous flow rate
indication is forcibly set to 0% (i.e., 4 mA), and both totalization
and pulse outputs are halted. This setting has precedence over the
output signal whenever an alarm occurs. When the 0% signal lock is
canceled, the instantaneous flow rate is restored in accordance with
the time constant originally set using B20/C11: Flow Damping.
The totalization display value is preset or reset to zero in
accordance with the external status input. The preset value is
determined using D21: Ttl Set Val Lower and D22: Ttl Set
Val Upper.
In case that “Start” is selected for D20: Total Execution, the
count for totalization starts from the preset value.
Status output is carried out when the forward internal
totalized value reaches or exceeds the totalization switch value.
The totalization switch value is determined using D23: Ttl
Switch Lower and D24: Ttl Switch Upper.
Status output is carried out when the instantaneous flow rate
equals or falls below the low flow rate limit (L), or when it equals
or exceeds the high flow rate limit (H). These limit values are
determined using G10: Low Alarm and G11: High Alarm.
Status output is carried out when the instantaneous flow rate equals
or falls below the low-low flow rate limit (LL), or when it equals or
exceeds the high-high flow rate limit (HH). These limit values are
determined using G12: Low Low Alarm and G13: High High
Alarm. To output “HH/LL Alarm” as an alarm, set G33: Alm-
HH/LL to “Yes.”