Glossary   
  CPU 31xC and CPU 31x, Technical data 
Glossary-6  Manual, Edition 08/2004, A5E00105475-05 
Error response 
Reaction to a runtime error. Reactions of the operating system: It sets the automation 
system to STOP, indicates the error, or calls an OB in which the user can program a 
reaction.  
ERTEC 
See ASIC
 
Fast Ethernet 
Fast Ethernet describes the standard with which data is transmitted at 100 Mbps. Fast 
Ethernet uses the 100 Base-T standard. 
FB 
See Function block
 
FC 
See Function
 
Flag bits 
Flag bits are part of the CPU's system memory. They store intermediate results of 
calculations. They can be accessed in bit, word or dword operations. 
Flash EPROM 
FEPROMs can retain data in the event of power loss, same as electrically erasable 
EEPROMs. However, they can be erased within a considerably shorter time (FEPROM = 
Flash Erasable Programmable Read Only Memory). They are used on Memory Cards. 
Force 
The Force function can be used to assign the variables of a user program or CPU (also: 
inputs and outputs) constant values. 
In this context, please note the limitations listed in the 
Overview of the test functions section 
in the chapter entitled Test functions, Diagnostics and Troubleshooting in the S7-300 
Installation manual
. 
Function 
According to IEC 1131-3, a function (FC) is a --> code block without --> static data. A 
function allows transfer of parameters in user program. Functions are therefore suitable for 
programming frequently occurring complex functions, e.g. calculations.