• TIA Portal datatypes (S7-1500 / S7-1200 / S7-400 / S7-300)
• Simatic classic datatypes (S7-400 / S7-300)
• TIA Data types codes
• Data-types
  • Pointer
  • Real
  • String
  • S5time
• Indirect addressing in Simatic Classic
• Indirect addressing in TIA Portal
  • TIA Portal slice access

List of data types used by Simatic S7. The page contains the more modern TIA variable types as well as the earlier S7-classic types.

There are four data types in: Boolean, Text, Numeric, and Date/Time. Each data type defines the format of information that can be entered into a data field and stored in your database.

An example above to the pointer: P#DB100.DBX14.0 WORD 4
The following elements make up a pointer:

You cannot use MOVE to access pointer data. This is because the Pointer is considered an “Any” data type, which MOVE does not accept. BLKMOV must be used instead, and in order to use that, Optimized Data must be turned off!

• Sign (of Mantissa) : 0: positive, 1: negative
• (Biased) exponent : The exponent field needs to represent both positive and negative exponents.
• (Normalised) mantissa : Mantissa is part of a number in scientific notation or a floating-point number, consisting of its significant digits.

String types in S7 are not NULL “terminated” like C-style strings. They instead have 2 “hidden” characters that precede the string data. The first hidden character is the maximum size of the string, which is 'n' in the example above, and the second hidden character is the actual length of the string (i.e. the number of characters stored).

So the string definition MyStr: STRING[10]:=“abcdef” would contain the following ASCII codes:

10, 06, 97, 98, 99, 100, 101, 102

10: maximum (declared) length of the character string
06: the current length of the string
97, 98: “a”, “b”,..

• Underscores in time and date are optional
• It is not necessary to specify all time units (for example: T# 5h10s is valid)
• Maximum time value = 9,990 seconds or 2H_46M_30S

In many cases, indirect addressing may be necessary in PLC technology. Its typical application is the preparation of signals for communication and SCADA, as well as the transformation of communication and SCADA signals and the “unpacking” of bits.

For example

• In the case of SCADA transmission, it is easier to use a WORD and transfer 16 bits in it
• Modbus communication is based on WORD registers. These are easy to handle with indirect addressing
• Many measuring units use two of the Modbus WORD registers (DWORD) to transfer one REAL. Structurally, DWORD and REAL are not the same, but the signals can be easily read with indirect addressing

• from Bit to: BYTE, WORD, DWORD
• from Byte to: WORD, DWORD
• from Word to: DWORD

bit := byte.%X1;    // bit 1 from byte
bit := word.%X4;    // bit 4 from word
bit := dword.%X11;  // bit 11 from dword 
 
byte := word.%B1;   // 2.byte from word
byte := dword.%B2;  // 3. byte from dword
 
word := dword.%W0;  // 1. word from dword

// FC Input : inWord (Word)
// FC output: 16 variable bit0..bit15 (Bool)
// splitting
#bit0 := #inWord.%X0;
#bit1 := #inWord.%X1;
#bit2 := #inWord.%X2;
#bit3 := #inWord.%X3;
#bit4 := #inWord.%X4;
#bit5 := #inWord.%X5;
#bit6 := #inWord.%X6;
#bit7 := #inWord.%X7;
#bit8 := #inWord.%X8;
#bit9 := #inWord.%X9;
#bitA := #inWord.%X10;
#bitB := #inWord.%X11;
#bitC := #inWord.%X12;
#bitD := #inWord.%X13;
#bitE := #inWord.%X14;
#bitF := #inWord.%X15;

// FC Input: 16 variable bit00..bit15 (Bool)
// FC Output : OUT (Word)
// JOIN
// Assemble bits to a word
#OUT.%X0 := #bit00;
#OUT.%X1 := #bit01;
#OUT.%X2 := #bit02;
#OUT.%X3 := #bit03;
#OUT.%X4 := #bit04;
#OUT.%X5 := #bit05;
#OUT.%X6 := #bit06;
#OUT.%X7 := #bit07;
#OUT.%X8 := #bit08;
#OUT.%X9 := #bit09;
#OUT.%X10 := #bit10;
#OUT.%X11 := #bit11;
#OUT.%X12 := #bit12;
#OUT.%X13 := #bit13;
#OUT.%X14 := #bit14;
#OUT.%X15 := #bit15;

This page has been accessed for: Today: 2, Until now: 391