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Warning
!
The TD 200 sets an M bit each time a function key is pressed. If you do not intend to use
function keys, and so do not assign an M byte address for function keys, the TD 200
defaults to byte M0 for the function keys. If your program uses bits in M0, and a user
presses any function key, the TD 200 sets the corresponding bit in M0, overwriting the
value assigned to that bit by your program.
Inadvertent changes to M bits could cause your program to behave unexpectedly.
Unpredictable controller operation could cause death or serious injury to personnel, and/or
damage to equipment.
Always reserve an M area address, even when your program does not utilize function
keys.
Figure 2-4 shows a referenced byte (MBn) and shows which bit of the byte is set by each
function key.
Figure 2-4
Bits Set by Each Function Key
The update rate selection determines how often the TD 200 polls the S7-200 CPU for
messages to display. The actual update time may be slower than the time that you select
because of the size of the message, the processing required, or network traffic.
For this example, select M0 and As fast as possible as shown in Figure 2-5.
TD 200 Configuration Wizard
Figure 2-5
Wizard: Function Key Memory Bits and Update Rate
SIMATIC TD 200 Operator Interface
C79000-G7076-C205-04
MSB
7
6
5
4
Shift
Shift
Shift
Shift
MBn
F4
F3
F2
F1
The TD 200 has 8 function keys (F1 through F4 and SHIFT F1 through SHIFT F4)
that are used to set memory bits in the CPU. You must reserve eight bits of memory
(M bits) for the TD 200 to set when a function key is pressed. One M bit is set by
the TD 200 each time the corresponding function key is pressed.
Which byte of M memory would you like to reserve for the TD 200?
0
The update rate determines how often the TD 200 polls the CPU for messages to
display. How often would you like the TD 200 to poll for messages?
As fast as possible
Configuring the TD 200
LSB
0
3
2
1
F4
F3
F2
F1
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