43
48-640 E3 Modulevel
®
Displacer Level Transmitter - F
OUNDATION
fieldbus
™
8.3.4 FF Segment Checklist
There can be several reasons for a F
OUNDATION
fieldbus
™
installation to be in a faulty condition. In order to assure
that communication can be established, the following
requirements must be met.
• Device supply voltage must be higher than 9 VDC with a
maximum of 32 VDC.
• Total current draw of a given segment cannot exceed the
rating shown on the power conditioner and/or barrier.
• Device polarity must be correct.
• Two 100
Ω
, 1 µF terminators must be connected to the
network—one at each end of the segment.
• Cable length plus spur length must not exceed the following
values:
• The cable shield is to be hard grounded only at one point
close to the DCS. In addition, the cable shield can be
capacitively grounded in multiple places to improve EMC
protection.
• Ensure all devices are on the “live list,” and the schedule has
been downloaded.
• Ensure the device identity is in the Resource Block.
• Ensure that the Resource Block, then the Transducer Block,
and lastly the Function Block(s) are in“Auto” mode rather
than Out of Service (OOS).
If all of these requirements are met, a stable communication
should be established.
number of Spurs
1 device
2 devices
3 devices
4 devices
25–32
—
—
—
—
19–24
100 ft. (30 m)
—
—
—
15–18
200 ft. (60 m)
100 ft. (30 m)
—
—
13–14
300 ft. (90 m)
200 ft. (60 m)
100 ft. (30 m)
—
1–12
400 ft. (120 m) 300 ft. (90 m)
200 ft. (60 m)
100 ft. (30 m)
Pair
Shield
twisted
Size
Length
type
Single
Yes
Yes
AWG 18 (0.8 mm2)
6,200 ft. (1,900 m)
A
Multi
Yes
Yes
AWG 22 (0.32 mm2)
3,900 ft. (1,200 m)
B
Multi
No
Yes
AWG 26 (0.13 mm2)
1,300 ft. (400 m)
C
Multi
Yes
No
AWG 16 (1.25 mm2)
650 ft. (200 m)
D
