Integral Blocks - Siemens SIMATIC S5-115U User Manual

S5-115U Manual
11

Integral Blocks

The following are integrated in the operating system of the central processing units:
• Some standard function blocks
• Some organization blocks
• A default DB1 for initializing internal functions.
Integral function blocks and organization blocks are programmed in machine language and so
execute at high speed. They do not use space in internal program memory.
Integral blocks are called in the control program like all other blocks; they can only be interrupted
by process interrupts.
(Integral) function blocks which can be called in the control program for special functions are the
subject of this chapter. Those blocks which the operating system of the CPU calls automatically
when specific events occur (e.g. programming errors, PLC faults) are not dealt with here (see
Chapter 7).
Block
Type No. Name
FB 238 COMPR
FB 239 DELETE
FB 240 COD : B4
FB 241 COD : 16
FB 242 MUL : 16
FB 243 DIV : 16
FB 244 SEND
FB 245 RECEIVE
FB 246 FETCH
FB 247 CONTROL
FB 248 RESET
FB 249 SYNCHRON
FB 250 RLG : AE
FB 251 RLG : AA
OB 31
OB 160
OB 251
OB 254
3
OB 255
3
DB 1
1 Execution time not including block-dependent compression
2 The execution time depends on the size of the data block to be transferred (see Section 11.1.3, "Frame Size")
3 See Section 2.6.2
EWA 4NEB 811 6130-02b
Table 11-1. Overview of Integral Blocks
Call Execution time
Length (in Millise-
(in Words) conds)
4 <
1
5 <
5 <
6 <
7 <
10 <
2
2
<
approx. 0.6
<
6.5 ms to 10 s
11
9
< 0.14
Function
0.6 Compress PLC memory
0.8 Delete block
0.8 4-tetrad BCD code converter
1.0 16-bit fixed-point converter
1.0 16-bit binary multiplier
2.3 16-bit binary divider
Send data
Receive data
4 Fetch data
Monitor job processing
4 Delete job
Initialize interface
2.0 Read analog value (see Chapter 10)
5.2 Output analog value (see Chapter 10)
Restart scan time
Variable time loop
2.0 PID control algorithm
Read digital inputs
Tranfer PIQ to outputs
Parameterize internal functions
Integral Blocks
11-1