Instruction manual

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INM4840-5 Nov 2007
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4.7 BPMH and BPSH Backplanes
4.7.1 BPMH16 and BPSH16 backplanes
The BPMH16 and BPSH16 backplanes are designed to carry:
16 x MTL4041A/B/P isolators, 16 x MTL4046/C/P isolators,
or a mixture of these isolators
1 x MTL4841 communications module
1 x MTL4842 HART interface module.
The hazardous area connections from the field devices go directly to
the isolator modules.
The safe area connections to the control system are as follows:
BPMH16 - Elco 8016 38-pin male connector
BPSH16 - screw-clamp connectors (2 per module).
4.7.2 VMPH16 mounting plate
To meet EMC requirements, the above backplanes must be mounted
on a VMPH16 mounting plate or on the metal surface of a cabinet or
panel. See Figure 4.11 for mechanical details.
The VMPH16 has threaded inserts (marked 'A' in Figure 4.11) and
is supplied with six mounting screws to enable the backplane to be
mounted onto it.
4.7.3 BPSH16-32 backplane
The BPSH16-32, MTL4000 Series HART backplane is designed
primarily for use with 16 (sixteen) of the MTL4044 dual-channel
analogue input modules. This backplane can also be used with the
MTL single channel isolators but not all 32 HART monitoring channels
can be used in this configuration.
A BPSH16-32R version is also available, fitted with 250 ohms input
resistors connected across the safe area control system connections.
The hazardous area connections from the field devices go directly to
the isolator modules.
Screw terminals are provided for the safe area interface to the control
system.
4.7.3 DC power connections
The BPxH16 backplanes have redundant power supply connections
and each supply input connector has dual pins for daisychaining the
supply. See Section 4.xx for connection details.
Power Voltage: 21–35V dc
Current: 1.35A ( 1.55A for BPSH16-32)
4.7.4 HART signal connections
The HART signals are routed to the MTL4842 module(s) by the
backplane and require no further connections.
4.2.5 Links between backplanes
Additional boards may be linked together to provide a total of sixteen
MTL4842 modules under one MTL4841 communications module.
Two 10-way connectors are provided (next to the MTL4841 module)
to link backplanes together, in the same way as shown in Figure
4.2.
See Section 4.8 for cabling recommendations and limits. MTL can
provide 10-way cables in a range of different lengths on request.
4.7.6 MTL48xx modules fitting and configuration
See section 5 for details.
4.7.7 RS485 communication connections
Two RS485 ports are provided on each board. These are used to
connect the BPHM64 backplane to the PC running the maintenance
software and to onward link to MTL4841 communications modules
on other backplanes.
Full details of this communications link are provided in Section
4.8.x.
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4.8 Backplane mounting
4.8.1 Using mounting plate VMPH16
Attach the backplane to the VMPH16 mounting plate using the screws
provided. Use mounting centres ‘D’ - shown in figure 4.11 - to attach
plate to required surface or structure.
4.8.2. Surface mounting
Surface mounting kit (type SMS01) is available for this purpose.
SMS01 contains 40 sets of the components shown in Figure 4.9.
Prepare panel
Refer to Figure 4.11.
a) Prepare holes in the mounting surface at the centres shown.
Thread these (M4) if retaining nuts will not be used.
Fit backplane
Refer to figures 4.9 and 4.10.
a) Select an M4 x 20mm screw (A).
b) Place a locking washer (B) and a plain washer (C) over it.
c) Insert the screw through a fixing hole on the baseplate.
d) Fit a 10mm spacer (D) and retain it with washer (E).
e) Repeat steps a) to d) for the other five (5) mounting holes.
f) Attach the baseplate using the prepared panel holes. Retain the
screws with a suitable nut if the holes are not tapped.
Figure 4.9 - SMS01 mounting kit components
Locking washer (B)
Plain washer (C)
M4 x 20mm screw (A)
Backplane
Retaining Washer (E)
M4 x 10mm
spacer(D)
Figure 4.10 - Surface mounting details