Siemens ET 200M, Manual, Page: 62 / 284

8-Channel Analog Output MTA
Marshalled Termination Assemblies for ET200M Remote I/O Modules
62 A5E00482820-12
6.3 Operation
Power is supplied via the two removable power connectors which are retained by
screws and marked L+A , MA, and L+B , MB . Each has circuitry to detect the
presence of voltage over 15 VDC and turn on the LED indicator. The LEDs are
marked A POWER and B POWER . There is also a connector ( J3 ) for a Power
Monitor board used to indicate the presence of both A and B power. See Section
19, Power Monitor Board (6ES7650-1BA02-0XX0).
Incoming power from
A
and
B
is diode OR’d, in CR106, to provide the MTA and
the module power from either input source. The output from CR106 is sent to the
I/O modules via the module fuses. Module Fuse 1 ( F100 ) supplies the I/O module
plugged into J1 and Module Fuse 2 ( F101 ) supplies power to the I/O module
plugged into J2. The channels do not require power from the I/O power supply and
therefore no channel power circuitry is required.
Field Terminals, C (
CHx+ ), Channel – ( CHx- ), and Shield ( SHx ), connect
to the field devices. CHx+ is the current output source and CHx - is the current
output sink. The I/O module outputs from J1 and J2 are diode OR’d, via CR1-
CR16, before connecting to CHx+ of the Field terminals. Redundant operation
uses two modules with one each connected to J1 and J2 , while non-redundant
systems have one module connected to either J1 or J2 .
The field termination connector is removable for ease of wiring maintenance and is
retained by friction.
6.4 Installation Requirements
See Section 2, Installation , before performing any installation and observe all
warnings
A common interconnecting cable (6ES7922-3BD00-0AS0 or 6ES7922-3BJ00-
0AS0), supporting eight analog output channels, interconnects the analog output
termination assembly to the 8-channel analog output module (6ES7 332-5HF00-
0AB0, E-Stand 3 or higher). See Figure 2-11.
It may be necessary to modify the printed circuit board as follows:
To separate channel input low from power supply common, cut and remove the
jumper W200 .
Note
To disconnect the interconnecting cable shield from ground at the MTA only, cut
and remove the shield disconnect jumper, W100 and W101 , for the associated
cable.
6.5 Maintenance
See Section 3, Maintenance , before performing any maintenance and observe all
warnings
Under normal operation, the
A/B Power LED
and
Module 1/2 Fuse LED
are on. If
both are off, check the power supply to MTA. If the A/B Power LED is off, check
the power supply to the MTA. If Module 1/2 Fuse LED is off, check the module
fuse and replace if necessary.