YOKOGAWA DPharp EJXC40A, Руководство пользователя

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<7. HART Communication>
7-26
IM 01C25W05-01EN
(3-3) Checking the event history (DTM only)
Event numbers can be used to view the past status
history of events that have occurred.
• Recalling event history
Recall
parameters
[Root menu] → Detailed setup →
Output condition → HART output →
Event Notification→ Acknowledge →
Acknowledge
Event
Notification
(method)
Get an event number and check the
history.
1. Get the event number.
Get the latest event number by following the
procedure below.
Execute the Acknowledge Event Notification
method.
1) Enter 0 in Read Event Notification.
2) OK
3) Check Event Number.
2. Check the event history.
View four events that have occurred including
the history of the event number that you
checked in step 1.
Execute the Acknowledge Event Notification
method.
1) Enter the event number that you checked in
step 1.-3) in Enter Event Number.
2) OK
3) History is displayed.
Example: If the event number that you checked
in 1.-3)is 123
Event Number Description
123 Last event
122 Second to the last event
121 Third to the last event
120 Fourth to the last event
7.2.3.18 Multidrop Mode
Up to 63 devices that have been set to multidrop
mode can be connected to a single communication
line.
To enable multidrop communication, the device
address must be set to any number ranging from 1
to 63.
When set to multidrop mode, all data are sent
digitally. Therefore, the 4 to 20 mA analog signal
output setting needs to be changed.
To set multidrop, follow the procedure below.
(1) Setting the polling address
Enter a value between 1 and 63 in the Poll addr
parameter.
• Recalling the polling address parameter (Poll
addr)
Recall
parameters
[Root menu] → Detailed setup →
Output condition → HART output →
Poll addr Set a number between 1 and 63 for the
address.
CAUTION
If the same polling address is assigned to
two or more transmitters in multidrop mode,
communication with these transmitters will not be
possible.
(2) Setting the analog output signal
Set Loop current mode to Disabled on the
transmitter side, and fixe the analog output signal to
4 mA DC. In this case, burnout output can no longer
be used. However, in the case of an application that
receives analog output signals to control devices,
analog output signals can be used on a single unit
for a single loop. In this case, set Loop current
mode to Enabled.
• Recalling Loop current mode and variables
Recall
parameters
[Root menu] → Detailed setup →
Output condition → Analog output →
Loop current mode →
Enabled 4 to 20 mA analog signal output mode
Disabled 4 mA DC fixed mode