Siemens SIMATIC TI505 Manual do Utilizador descarregar pdf (Página 48)

Modbus Commands

2-17

SIMATIC TI505/TI500 MODNIM User Manual

Code

07 instructs the MODNIM to read 8 predefined coils within a

secondary.

This implementation will read the first 8 coils (first 8 Ys or first 8 Cs,

depending on the position of the dipswitch) in the discrete image register in

a secondary and pack them into one data byte.

NOTE:

The programmer of a non-Modbus PLC must make certain that the

application program running within the PLC will place meaningful data in

these locations. This data can reflect status information.

[This command is equivalent to TIW

Y Primitive 20 using TT types 04, 07

(Y unpacked, packed) or TT types 05, 08 (C unpacked, packed), from

locations 1 – 8, depending on the position of configuration Switch 10.]

Example:

Request: 11 07 XXXX

Checksum (XXXX)

Function code (07)

Slave address (11)

Figure 2-18 Read

Exception Status Example — Request

This request to secondary 17 (decimal) is asking for exception status data.

Response: 11 07 3B XXXX

Checksum (XXXX)

Data value (3B)

Function code (07)

Slave address (11)

Figure 2-19 Read

Exception Status Example — Response

Code 07 — Read

Exception Status

1 2 ... 43 44 45 46 47 48 49 50 51 52 53 ... 90 91

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