Input/output blocks
1-2
Function Blocks - FM 458-1 DP
Edition 12.2004
1.1 SBM Rotary encoder block
SBM
hardware address
―
GV AD
YPI
DI
―
position in increments
encoder type
―
I TYP RPI
DI
―
max. increments/revolution
baud rate
―
I BDR
Y
R
―
normalized speed
resolution
―
I EXP
U
I
―
revolutions
alarm- or normal FP
―
BO DM
QF
BO
―
group error message
rated speed
―
R RS
YF
DW
―
error detection
The SBM function block is used to realize the following tasks:
•
Initialize the rotary encoder, which is connected at the SBM2 module
•
Determine the position and speed from the encoder data
•
Error handling when communication errors develop between the
encoder and SBM2 module
During the initialization phase of the system, the initialization I/O are read
and the appropriate mode set at the SBM2 module. The following
settings are made for the EQN1325 encoder:
•
The encoder power supply is set to 5 V
•
Number of revolutions to 4096
•
Signal periods per revolution 8192
After the mode has been set, the zero position is determined, and the
starting values for the position and the speed output at the connections.
In the standard mode, the block can assume four different statuses:
•
NRM
The values read-out from the SBM2 module (position and speed) are
displayed at the block connections. If an error is detected, the block
goes into the ERR error condition.
•
ERR
The following errors can occur in operation:
•
Encoder is defective or is not connected
•
Encoder was disconnected
•
Data transfer error for serial communications between the encoder
and SBM2 module
•
SBM2 module not available
In the first three cases, the block goes into the "INI“ initialization
status and in the latter case into the "OFF" status.
Symbol
Brief description
Mode of operation
