Yokogawa EJA115 - Manual (Page 24)

IM 01C22T01-01E 2-17
2. HART COMMUNICATOR OPERATION
(17) 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 also is disabled.
Setting of Multidrop Mode
F0235.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. EJA:
Poll addr
O
0
HELP DEL ESC ENTER
HART Communicator
Auto Poll
No
No
Yes
DEL DEL ESC ENTER
Call up the Auto Poll and set to
Yes.
HELP (ENTER)
1. Device setup
4. Detailed Setup
3. Output condition
4. HART Output
1. Poll addr
Online
Utility
Auto Poll
NOTE
1. When the address is set and the multi-drop
mode is set to “No” at the same time, Online
menus cannot be called up and displayed. Be
sure to turn the multidrop mode to “Yes” after
setting the address with “Poll addr.”
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
F0236.EPS
(1) The HART communicator
searches for the transmitter that
is set in the multi-drop mode
when the HART communicator
is turned on.
When the HART communicator
is connected to the transmitter,
the manufacturer’s x’ter type
code 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 is
slow in this case (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 EJA110-1
2 EJA110-2
3 EJA110-3
HELP SET HOME OK
EJA:EJA110-1:
Online
1 Device setup
2 Pres 0.00 mmH2O
3 A01 Out .000 mA
4 LRV 0.00 mmH2O
5 URM 3500.00 mmH2O
DEL SET ABORT OK
2
2 HART Communicator
1 Offline
2 Online
3 Transfer
4 Frequency Device
5 Utility
HELP DEL ABORT OK
3
3
Example: Communication when set in the multi-drop mode
To Release the Multi-drop Mode:
Follow the procedure below.
1. Call up the Poll addr display, and set the address
to 0.
2. Call up the Auto Poll display, and set to No .
(18) External Switch Mode
• Enabling/inhibiting zero point adjustment using the
external zero-adjustment screw on the transmitter.
Follow the procedure below to enable or inhibit zero
point adjustment from the zero-adjustment screw on
the transmitter.
This is set to ENABLE when the instrument is
shipped.
F0237.EPS
(ENTER)
EJA:
Ext SW mode
Enable
Enable
Inhibit
HELP SEND ESC ENTER
Select Inhibit and press ENTER
(F4).
Press SEND (F2) to send the data.
(SEND)
1. Device setup
4. Detailed setup
5. Device information
1. Field device info
7. Ext SW mode
Example: Inhibiting zero adjustment by the external zero-
adjustment screw