Siemens SINUMERIK 840Di sl Commissioning Manual page 207

Several MCPs
A maximum of 2 machine control panels are supported by the basic PLC program. The
communication parameters of the MCP are called MCPx... (x = 1 or 2) in function block FB1.
To synchronize several MCPs, the PLC program must be adapted accordingly. This is the
user's (machine manufacturer's) responsibility.
MCP failure
The basic PLC program detects an MCL failure even if no data is exchanged between MCP
and PLC. For instance, after a PLC restart.
The monitoring function is activated as soon as all components have signaled "Ready" after
powerup.
An alarm is displayed on the user interface if an MCP fails:
● 1. MCP alarm: "400260 Failure of machine control panel 1"
● 2. MCP alarm: "400261 Failure of machine control panel 2"
References
For a detailed description of the PLC basic program or of function block FB 1, please refer to:
/FB1/ Function Manual - Basic Functions; P3 Basic PLC Program, Chapter "FB 1: RUN_UP
Basic program, startup section
Manual
Commissioning Manual, 05/2008, 6FC5397–4CP10–4BA0
Note
An HT 8 is connected to the PCU via Ethernet. Since the communication of the MCP with
the SINUMERIK PLC is based on Windows components, the MCP monitoring time may
be exceeded in the following cases:
• 1. Cause: Windows XP identifies a fatal exception error (blue screen)
Possible measure: none
• 2. Cause: Impairment of Ethernet communication through unsuitable PC components.
Possible measure: Increase in MCP monitoring time (parameter: MCPxTimeout)
Ethernet communication
7.6 HT 8
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