Prosoft-technology MVI56E-MCMR Manual de usuario descargar pdf (Pagina 188)

Reference MVI56E-MCMR ♦ ControlLogix Platform

User Manual Modbus Communication Module with Reduced Data Block

Page 188 of 225 ProSoft Technology, Inc.

May 13, 2014

The data fields in responses to other kinds of queries could contain error counts

or other data requested by the sub-function code.

6.6.9 Force Multiple Coils (Function Code 15)

Query

This message forces each coil in a consecutive block of coils to a desired ON or

OFF state. Any coil that exists within the controller can be forced to either state

(ON or OFF). However, because the controller is actively scanning, unless the

coils are disabled, the controller can also alter the state of the coil. Coils are

numbered from zero (coil 00001 = zero, coil 00002 = one, and so on). The

desired status of each coil is packed in the data field, one bit for each coil (1=

ON, 0= OFF). The use of Slave address 0 (Broadcast Mode) will force all

attached Slaves to modify the desired coils.

Note: Functions 5, 6, 15, and 16 are the only messages (other than Loopback Diagnostic Test) that

will be recognized as valid for broadcast.

The following example forces 10 coils starting at address 20 (13 HEX). The two

data fields, CD =1100 and 00 = 0000 000, indicate that coils 27, 26, 23, 22, and

20 are to be forced on.

Adr

Func

Hi Add

Add

Quantity

Byte

Cnt

Data Coil Status

20 to 27

Data Coil Status

28 to 29

Error Check

Field

CRC

1 2 ... 183 184 185 186 187 188 189 190 191 192 193 ... 224 225

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Prosoft-technology MVI56E-MCMR Manual de usuario Pagina 188