IM 01C25T01-01E
3-21
3. OPERATION
3.5.10 Multidrop Mode
“Multidropping”
transmitters refers to the connection
of several transmitters to a single communications
transmission line. Up to 15 transmitters can be con-
nected when set in the multidrop mode. To activate
multidrop communication, the transmitter address must
be changed to a number from 1 to 15. This change
deactivates the 4 to 20 mA analog output, sending it to
4 mA. The alarm current is also disabled.
Setting of Multidrop Mode
F0335.EPS
Call up the
Poll addr
and set the
polling address. (a number from 1 to
15)
And press
SEND (F2)
to send the
data.
EJX:
Poll addr
0
1
HELP
DEL
ESC
ENTER
HART Communicator
Polling
Ask Before Polling
Ask Before Polling
Always Poll
Digital Poll
Poll Using Tag
HELP
DEL
ESC
ENTER
Confirm that
Always Poll
,
Ask
Before Polling
, or
Digital Poll
is
specified, and press
ENTER (F4)
.
(ENTER)
1. Device setup
4. Detailed Setup
3. Output condition
3. HART Output
1. Poll addr
2. Online
4. Utility
1. Configure Communication
1. Polling
•
Then make sure the communicator setting is as follows.
NOTE
1. When the polling option is set as
Never Poll
or
Poll Using Tag
, the online menus cannot
be called up and displayed. Be sure to select
a polling option such as
Ask Before Polling
.
2. When the same polling address is set for two
or more transmitters in multidrop mode,
communication with these transmitters is
disabled.
1
1
1
F0336.EPS
(1) The HART communicator
searches for a transmitter that is
set in multidrop mode when it is
turned on.
When the HART communicator
is connected to the transmitter,
the polling address and the tag
will be displayed (display ).
(2) Select the desired transmitter.
After that, normal
communication to the selected
transmitter is possible. However,
the communication speed will be
slow (display ).
(3) To communicate with another
transmitter, turn off the power
once and then turn on it again,
or call up display and select
Online
.
(4) Display will appear. Select
the desired transmitter.
HART Communicator
Online
1 EJX110A-1
2 EJX110A-2
3 EJX110A-3
HELP
SET
HOME
OK
EJX:EJX110A-1:
Online
1 Device setup
2 Pres 0.0 mmH2O
3 AO 4.000 mA
4 LRV 0.0 mmH2O
5 URV 3500.0 mmH2O
DEL
SET
ABORT
OK
2
2
HART Communicator
1 Offline
2 Online
3 Frequency Device
4 Utility
HELP
DEL
ABORT
OK
3
3
Example: Communication when set in multidrop mode
To release multidrop mode, follow the procedure
below.
1. Call up the
Poll addr
display and set the address
to 0.
2. Call up the
Polling
display and set
Ask Before
Polling
.
