PSM Logic Functions, Logic Block Function - GF54.21-S-3210TRA

Model 447 

With Code ED5 (Parameterisable special module) 

Except Code XM7 (MOPF II) 

Model 448 

With Code ED5 (Parameterisable special module) 

Except Code XM7 (MOPF II) 

Courtesy of MERCEDES-BENZ USA

Logic block, function 

A logic block has 4 digital inputs (E₁ , E₂ , E₃ , E₄ ) and 2 digital outputs (A_A , A_B ), whereby the 2nd output is always the inversion of the 1st output. A codable filter is connected in series to every input.

In one logic block, 3 2-input gates are configured according to the illustration above. These 2-input gates can perform various logic functions independently of one another. By these means, it is possible to effectively realize logic operations which for the most part consist of 2-input gates, without having to use a complete logic block each time. At the same time, there is also the option to simulate 3-input and 4-input gates with just one logic block. This procedure saves resources and shortens the throughput time of the system of the programmable logic controller (PLC), as the number of sequential blocks can be reduced.

For the definition of the logic functions in block X (X), block Y (Y) and block Z (Z), one byte with the following structure is provided for each logic block:

Coding of logic block 

Courtesy of MERCEDES-BENZ USA

For block Z, 2 bits are sufficient for coding, as the "NAND" and "EXNOR" functions are already automatically provided by the 2nd inverting output of the logic system.

Signal identification number = Signal ID.

Designation in data entry table	Data entry bit width	Data bit evaluation	Meaning
B1_G1_LB1_Sub-block_X	3 bit	-	Codable block X
B1_G1_LB1_Sub-block_Y	3 bit	-	Codable block Y
B1_G1_LB1_Sub-block_Z	2 bit	-	Codable block Z
B1_G1_LB1_1_Signal_ID	32 bit	1 bit	Filter + input signal data entry signal ID for Eingang 1
B1_G1_LB1_2_Signal_ID	32 bit	1 bit	Filter + signal ID for input signal data entry for Eingang 2
B1_G1_LB1_3_Signal_ID	32 bit	1 bit	Filter + signal ID for input signal data entry for Eingang 3
B1_G1_LB1_4_Signal_ID	32 bit	1 bit	Filter + signal ID for input signal data entry for Eingang 4

Designation in signal ID list	Data bit width	Meaning
Out_G1_LB1	1 bit	Signal ID of the logic block output
Out_G1_LB1_inv	1 bit	Signal ID of the inverted logic block output

The same applies for the other logic blocks making allowance for the naming convention:

• "B<Block number>_G<Group number>_LB<Number>..."
• "Out_G<Group number>_LB<Number>..."

	Parameterizable special module (PSM) control unit component description		GF54.21-S-5005TRA
	Overview of system components for parameterizable special module (PSM)		GF54.21-S-9998TRA