Getting started, 1 connection of devices, Getting started -1 – Yokogawa EJX115A User Manual
Page 17: Connection of devices -1
<4. Getting Started>
4-1
IM 01C25T04-01EN
4. Getting Started
PROFIBUS PA is fully dependent upon digital
communication protocol and differs in operation
from conventional 4 to 20 mA transmission.
HMI
Class 1 Master
I/O CARD, PLC, etc.
PROFIBUS-DP
PROFIBUS-DP devices
PROFIBUS-PA devices (DPharp)
PROFIBUS-PA (31.25 kbps)
Class 2 Master
FieldMate (FDT/DTM)
PDM (EDD), etc.
DP/PA
Coupler
F0401.ai
Figure 4.1
Profibus System Construction
4.1 Connection of Devices
The following are required for use with PROFIBUS
PA devices:
• Power supply:
PROFIBUS PA requires a dedicated power supply.
It is recommended that current capacity be well
over the total value of the maximum current
consumed by all devices.
Power is supplied by a DP/PA coupler.
• Terminators:
PROFIBUS PA requires two terminators.
A terminator shall be located at each end of the
trunk cable.
• Field devices:
Connect the PROFIBUS PA communication type
field device. Two or more transmitters or other field
devices can be connected.
• DP/PA Couplers:
PROFIBUS PA requires DP/PA couplers which
convert the RS-485 signals to the IEC 61158-2
signal level and power the field devices via the
PROFIBUS PA.
• Cable:
Refer to Table 4.1.
Table 4.1
PROFIBUS PA Cables and
Transmissible Length
Type of cable
Cable
specifications
Max. length
of cable
(reference
value)
Type A: Individually-
shielded twisted pair
cable
#18AWG
(0.82 mm
2
)
1,900 m
Type B: Overall-
shielded twisted pair
cable
#22AWG
(0.32 mm
2
)
1,200 m
Type C: Unshielded
twisted pair cable
#26AWG
(0.13 mm
2
)
400 m
Type D: Overall-
shielded non-twisted
cable
#16AWG
(1.25 mm
2
)
200 m
Note: Yokogawa recommends the use of Type A.
Usage of Type B and D is restricted.
Yokogawa does not recommend the use of Type C.
SUPPLY
CHECK
or
ALARM
+
–
+
–
Power supply and output terminal
Not used for PROFIBUS Communication type
Ground terminal
Communication
terminals
connection hook
*1: Not available for PROFIBUS communication type.
Check meter
connection hook
*1
SUPPLY +
SUPPLY –
CHECK – or ALARM –
*1
CHECK + or
ALARM +
*1
+
–
F0402.ai
Figure 4.2 Wiring Diagram