Siemens SIMATIC RF300 - Communication between Communication Module, Reader (with RS 422 Interface) and Transponder

RF300 system planning
4.1 Fundamentals of application planning
SIMATIC RF300
4-12 System Manual, Release 04/2006, J31069 D0166-U001-A2-7618
4.1.10 Communication between communication module, reader (with RS 422 interface)
and transponder
Communication between the communication module, reader and transponder takes place
asynchronously through the RS 422 interface. Depending on the communication module
(ASM) used, transmission rates of 19200 bytes, 57600 bytes or 115200 bytes can be
selected.
Calculation of the communication time for interference-free transfer
The communication time for fault-free data transfer is calculated as follows:
(1)
Calculation of the maximum amount of user data
The maximum amount of user data is calculated as follows:
t
k
: Communication time between communication module, reader and transponder
t
v
: Dwell time
n: Amount of user data in bytes
n
max
: Max. amount of user data in bytes in dynamic mode
t
byte
: Transmission time for 1 byte
K: Constant; the constant is an internal system time. This contains the time for
power buildup on the transponder and for command transfer
(1) If the transmission is interrupted briefly due to external interference, the
communication module automatically continues the command.