Siemens S7-1200 System Manual page 357

The following four tables show a binary breakdown of the four bytes of data that are being
analyzed:
Table 8- 136 Example 1: No errors: A value of 0xFFFF_1F00 is returned for MODE 1 (Module
Byte with value
Slots 1 (Bit 1) through 20 (Bit 20) contain modules. Slot 21 (Bit 21) and beyond do not contain
Table 8- 137 Example 2: A module has been pulled from PROFINET slave device "et200s_1". A value
Byte with value
Only module 15 (Bit 15) is marked as defective. All other modules are functional.
Table 8- 138 Example 2 (continued): A module has been pulled from PROFIBUS slave device
Byte with value
Module 15 (Bit 15) is shown as missing. Modules 1 through 14 (Bits 1 through 14) and 16 through 20
S7-1200 Programmable controller
System Manual, 03/2014, A5E02486680-AG
configuration active).
Bit pattern with value
Byte 1 0xFF Bit 7 1111-1111 Bit 0
Byte 2 0xFF Bit 15 1111-1111 Bit 8
Byte 3 0x1F Bit 23 0001-1111 Bit 16
Byte 4 0x00 Bit 31 0000-0000 Bit 24
modules..
MODE 4 (Module exists) data matches MODE 1 (Module configuration active), so the configured
modules match the existing modules.
of 0x0180_0000 is returned for MODE 2 (Module defective).
Bit pattern with value
Byte 1 0x01 Bit 7 0000-0001 Bit 0
Byte 2 0x80 Bit 15 1000-0000 Bit 8
Byte 3 0x00 Bit 23 0000-0000 Bit 16
Byte 4 0x00 Bit 31 0000-0000 Bit 24
"et200s_1". A value of 0xFF7F_1F00 is returned for MODE 4 (Module exists).
Bit pattern with value
Byte 1 0xFF Bit 7 1111-1111 Bit 0
Byte 2 0x7F Bit 15 0111-1111 Bit 8
Byte 3 0x1F Bit 23 0001-1111 Bit 16
Byte 4 0x00 Bit 31 0000-0000 Bit 24
(Bits 16 through 20) are shown as existing.
8.5 Diagnostics (PROFINET or PROFIBUS)
Notes
Bit 0 is true; data is available.
Notes
Bit 0 is true; data is available.
Notes
Bit 0 is true; data is available.
Extended instructions
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