Siemens SIMATIC S5 Series, Manual

Page: 27 / 109

S5-95U, Second Serial Interface Point-To-Point Link
2.3 Coordination Bytes in a Point-To-Point Link
The
”
receive
”
and
”
send
”
coordination bytes control data traffic between the partners. The
meaning of the bits in the coordination bytes is explained below.
”
Send
”
coordination byte (KBS) (flag byte or high-order byte in the data word)
Error
0: No error
1: Send error during last data transfer
SEND-ERL (send permission)
0: Program can access send mailbox. Operating
system has no access.
1: Operating system sends data from the send
mailbox to the bus. Program has no access.
2
7
2
0
R W/R
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
Figure 2-6 Structure of the Coordination Bytes
LAN RUN
0: SINEC L1 LAN is in STOP mode
1: SINEC L1 LAN is in RUN mode
”
Receive
”
coordination byte (KBE) (flag byte or high-order byte in the data word)
Error
0: No error
1: Receive error during last data transfer
Slave-AUS
0: Normal operation
1: Partner failed
2
7
2
0
R R R W/R
a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a
Irrelevant bits
R: Read Only (bit may only be read)
W/R: Write / Read (bit may be read and overwritten)
a a a a a a a
a a a a a a a
a a a a a a a
EMPF-ERL (receive permission)
0: Program can fetch data from the receive
mailbox. Operating system has no access.
1: Operating system can transfer data from the
bus to the receive mailbox. Program has no
access.
The coordination bytes, the send mailbox and the receive mailbox are parameterized at the SI1
interface in DB1 as in the case of SINEC L1 ( see S5-90U/S5-95U System Manual, Section 14).
EWA 4NEB 812 6095-02
2-7