Diagnostics Via As-Interface; General Procedure - Leuze lumiflex ASM1E Connecting And Operating Instructions

Attention!
Please note that accessing the configuration stored in the AS-interface safety monitor
can affect the reliability of the system. Changes to validated configurations should only
be made by authorised personnel. All changes must be made in accordance with the
instructions given in the user manual supplied with the asimon configuration software.
Notice!
If no valid configuration has yet been stored in the AS-interface safety monitor, the
default password "SIMON" is valid.
11

Diagnostics via AS-Interface

11.1

General procedure

Notice!
The assignment of an AS-i slave address for the AS-i safety monitor is a
prerequisite for diagnosing the AS-i safety monitor on the AS-i master.
Using the AS-i bus, diagnosis of the AS-i safety monitor and configured modules is
possible from the AS-i master, normally a PLC with master module.
However, to ensure reliable transmission and efficient evaluation of the diagnostic
data, a series of requirements must be satisfied:
• Relatively long telegram propagation times may occur, particularly when using an
additional bus system between PLC and AS-Interface. Owing to the asynchronous
transmission in the master in the case of two successive, identical data calls, the
PLC may not necessarily know when the AS-interface safety monitor is responding
to the new call. Thus, the answers to two successive, different data calls should
differ by at least one bit.
• The diagnostic data must be consistent, i.e. the status information sent by the
AS-interface safety monitor must match the actual module states, especially if the
propagation time to the PLC is longer than the updating time in the AS-interface
safety monitor (approx. 30 ... 150ms).
• Whether a deactivated relay of an output circuit represents the normal state
depends on the operating mode of the AS-interface safety monitor. The diagnostics
in the PLC should only be called in the event of a deviation from the normal state.
The diagnostic procedure described below satisfies these requirements and should
therefore always be followed.
Diagnostic procedure
The PLC always queries the AS-interface safety monitor alternately with two data calls
(0) and (1). These data calls return the basic information (state of the output circuits,
protective/configuration operation) to allow a diagnosis. The AS-interface safety
monitor answers the two calls with the same user data (3 bit, D2 ... D0). Bit D3 is a
control bit, similar (but not identical) to a toggle bit. D3 is 0 for all even data calls (0); D3
is 1 for all odd data calls (1). This enables the PLC to detect whether the answer has
changed.
Data calls (0) and (1) return the answer X000 if the normal state exists (protective
operation, everything OK). For devices with only one output circuit and with two
dependent output circuits, output circuit 2 is always marked as OK. With two
ASM1, ASM1E 99