Siemens SIMATIC TD 200, User Manual

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D-14
SIMATIC TD 200 Operator Interface
C79000-G7076-C272-01
If you have more than one format word in a message because you have more than
one embedded value in the message, you only need to set the acknowledge bit in
the first format word of the message. The TD 200 ignores the acknowledge bit in
all subsequent format words of the message.
When a message requiring acknowledgement is enabled for display:
The TD 200 displays the message and causes it to flash.
The message is not removed or replaced on the TD 200 display, and continues
to flash, until the operator acknowledges it by pressing ENTER.
The TD 200 sets the acknowledge-notification bit and removes the message
after the operator presses ENTER.
See Section D.5 for more information about how the TD 200 processes messages
with acknowledgement.
Acknowledge-Notification Bit 1
The S7-200 CPU program uses the acknowledge-notification bit to note that the
operator has seen and acknowledged a message. To acknowledge a message,
1. Move the cursor to the display line requiring acknowledgement and
2. Press ENTER.
After the operator presses ENTER, the TD 200 sets the acknowledge-notification
bit. The S7-200 program uses the acknowledge-notification bit to note that the
operator has acknowledged the message. You must design your S7-200 program
to reset this bit if you want subsequent notification. Figure D-12 shows the
acknowledge-notification bit, located in byte 0 of the format word.
A N - Acknowledge-Notification
0 - Not acknowledged
1 - Message Acknowledged
Format Word Optional Data Value
Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5
MSB of
Format
LSB of
Format
MSB of
Data
LSB of
Data
0
0
0 E P EN A
7 6 5 4 3 2 1 0
MSB LSB
AN
Figure D-12 Acknowledge-Notification Bit of Byte 0 of the Format Word
TD 200 Parameters and Messages