Siemens SIMATIC S5 Manual page 105

2 Engineering
Test and diagnostics of communication in the SIMATIC S5
To monitor the send/receive communication of scenario 3 in the SIMATIC S5-CPU,
call the watch table "BB55" in STEP 5.
The count value (3) is cyclically written in the S7-1500 CPU every second and the
mirrored incremented value is received again (4).
The communication and connection status of the handling blocks SEND (1) and
RECEIVE (2) can be evaluated via the indicator words (ANZW) of the HTBs.
Ethernet Communication (ISO on TCP) between SIMATIC S5 and
SIMATIC S7-1500 Controllers
Entry-ID: 109482475, V1.2, 07/2019
1
3
2
4
105