<2. Preparation>
2-1
IM 12A01A02-72E
3rd Edition : Oct. 01, 2015-00
2. Preparation
The FLXA21 PROFIBUS PA is provided with three cable glands. The first is used for the
electrode wiring as the other is used for the power wiring shown in figure 2.1.
For sensor cable
For power supply
For grounding cable
Figure 2.1
Cable gland diagram
2.1
Cables, terminals and glands for PROFIBUS
PA
Wire and install the system by referring to chapter 2 in the FLXA21 instruction manual (IM
12A01A02-01E).
The PROFIBUS PA power supply is 9 to 32 V DC. The wiring is the same.
However, for the PROFIBUS PA cables see Table 2.1.
Table 2.1 PROFIBUS PA Cables and transmissible Length
Parameters
Conditions
Type A
Type B
Type C
Type D
Max DC Resistance, Ω/km per conductor
22
56
132
20
Max Attenuation, dB/km
1.25 f, (39 kHz)
3.0
5.0
8.0
8.0
Gauge
—
#18 AWG
(0.82 mm
2
)
#22 AWG
(0.32 mm
2
)
#26 AWG
(0.13 mm
2
)
#16 AWG
(1.25 mm
2
)
Max Length, meters
—
1,900
1,200
400
200
Note: 1900 m is trunk + sum of Spurs (Max length type A cable)
Yokogawa recommends the use of Type A.
Usage of Type B and D is restricted.
Yokogawa does not recommend the use of Type C.
Table 2.2 Recommended length of Spur Cables
Number of spur cables Length of a non-intrinsically
safe spur cable
15-16
60 m
13-14
90 m
1-12
120 m
Note: • 1 device per spur.
• Keep as short as possible (min 1 m)
