Acromag 961PB-2006, Руководство пользователя

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BusWorks®
961/962PB Module User’s Manual ProfiBus Differential I/V Input
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Acromag, Inc. Tel:248-624-1541 Fax:248-624-9234 Email:
sales@acromag.com http://www.acromag.com
14
8
EF
0
2
1
D
C
3
4
8
0
EF
D
C
2
3
4
9
A
B 5
6
7
B
9
A
5
6
4
-6V
5V
1
+6V
RTS
IN5+
IN3+
IN4-
IN3-
IN0-
IN1-
IN1+
IN2+
M
U
X
MUX
+6V
5V
7
4
SHLD
DB9
IN4+
IN5-
IN2-
IN0+
-6V
M
U
X
+
AIN2
-
+5V
+
AIN1
-
PWR
LED
+5V
BUS
LED
+5V
12-36VDC
P
O
W
E
R
N
E
T
W
O
R
K
BIAS
-6V
+6V
-6V
+6V
NEG VOLTAGE
CONVERTER
INPUT/LOGIC
POWER
NETWORK
POWER
MICRO
CONTROLLER
ISOLATED
FLYBACK
SWITCHER
RS485
PROFIBUS
TRANSCEIVER
DC+
DC-
+1.6V
ISOLATED INPUT POWER
ISOLATED RS485
ISOLATED SECONDARIES
ADDRESS
BUFFER
A/D
CONVERTER
PROFIBUS
SPC3 SLAVE
ASIC
INPUTS 0, 1, & 2 MUST
BE SAME RANGE
INPUTS 3, 4, & 5 MUST
BE SAME RANGE
961/962PB SIMPLIFIED SCHEMATIC
These input modules provide up to 6 process current (961PB), or 6
differential DC voltage (962PB) input channels, and an isolated RS485
ProfiBus interface for configuring and monitoring the input channels. The
current input model uses precision 24.9Ω current sink resistors across the
inputs. Voltage input models use 10:1 precision resistor voltage dividers at
the input. A multiplexer is used to connect each input voltage to an A/D
converter (separate A/D channels serve 3 input channels each). The A/D
converter then applies appropriate gain to these signals, performs analog-to-
digital conversion, and digitally filters the signals. The digitized A/D signal is
then transmitted serially to a microcontroller. The microcontroller completes
the transfer function according to the input range per its embedded program.
Configuration and calibration parameters are stored in non-volatile memory
integrated within the microcontroller. These modules implement the
ProfiBus protocol via an industry-standard SPC3 ASIC from Siemens. This
ASIC acts like a RAM or UART chip to the internal microcontroller and
completely handles the requirements of the protocol standard. The ASIC will
transfer network data to the microcontroller and automatically provide the
response to the bus. The ASIC handles the ProfiBus protocol and
communicates with the network via an optically isolated RS485 transceiver.
A wide input switching regulator (isolated flyback) provides isolated power to
the input circuit and the RS485 port. Refer to the simplified schematic below
to gain a better understanding of the circuit.
HOW IT WORKS