Manual 37140A
MFR 11 - Protection Relay
Page 66/80
© Woodward
Framework Data for the Interfaces
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Framework Data to Procedure 3964 (TTY, RS-232, RS-485)
String length ....................... 8 bit
Stop bit................................ 1 bit
Parity bit ............................. 1 bit with even parity
Idle state.............................. This corresponds to the state log. "1" (20 mA with TTY)
Data format ......................... 16 bit binary value
Transmission rate................ 9,600 Baud.
Other baud rates on request. The records are transferred cYClically.
RK 512 interpreter procedure:
See Siemens documentation on procedure 3,964.
Framework Data for Hardware Handshaking RTS/CTS (RS-232, RS-422)
String length ....................... 8 bit
Stop bit................................ 1 bit
Parity bit ............................. 1 bit with even parity
Idle state.............................. This corresponds to the state log. "1" (20 mA with TTY)
Data format ......................... 16 bit binary value
Transmission rate................ 9,600 Baud.
Other baud rates on request. The records are transferred cyclically.
Procedure:
When the transmitter is ready for data transmission, it notifies the receiver of this by switching its
control line RTS to "ON". The prerequisite of this is that no data are received (CTS = "OFF"). The receiver regis-
ters this status and indicates its readiness to receive by switching its RTS line to "ON". The transmitter can then
begin transmitting when it detects this "ON" status on its CTS line. As soon as the receiver withdraws its RTS
signal (RTS = "OFF"), the transmitter interrupts its transmission and waits until the receiver is ready to receive
again. The initialization conflict (both subscribers set the RTS line simultaneously) and timeout (one subscriber
waits in vain for a reply) must be taken into consideration.
Framework Data for Modbus RTU Slave
Transmitting protocol ......... Modbus RTU slave
Hardware ............................ Interface RS-485
Transmission rate................ adjustable
Slave address ...................... adjustable
Parity................................... adjustable
A maximum of 10 words can be read or 4 words written with one command. Modbus function codes 03, 04, 06
and 16 are supported.
MFR 1
2005-08-31 | Data coupling 2005-08-31.skf
PI
N
5
GND
R
S
-485
External device
PLC
A = not-inverted
B = inverted
GND
R
S
-485
X3
X1
X2
A
B
X4
X5
7
2
RS-485 Modbus RTU Slave
A
B
Figure 7–2: Interface - Modbus connection
