App index – Yokogawa Button Operated MV2000 User Manual

Page 124

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5-5

IM MV1000-17E

Responses

1

2

3

4

5

6

7

App

Index

if(odd){

/* When the data length is odd */

union tmp{

/* Pad with a 0, and add to the unsigned short data. */

unsigned short s;
unsigned char

c[2];

}tmp;
tmp.c[1] = 0;
tmp.c[0] = *((unsigned char *)p);
csum += tmp.s;
}
if((csum = (csum & 0xffff) + ((csum>>16) & 0xffff)) 0xffff)

/* Add the overflowed digits *

csum = csum - 0xffff;

/* If the digit overflows again, add a 1. */

return((~csum) & 0xffff);

/* bit inversion */

}

RS-422/RS-485 Responses

The following table shows RS-422/RS-485 interface commands and their responses.

Command

Syntax

Description

Response

ESC

Oxx CRLF

Opens a device

• Response from the device with the specified address

ESC Oxx CRLF

• No response if the device with the specified address

does not exist

*

ESC

Cxx CRLF

Closes a device

• Response from the device with the specified address

ESC Cxx CRLF

• No response if the device with the specified address

does not exist

*

* Possible reasons for not finding a device with the specified address are: (1) there is an error in

the command, (2) the specified address does not match the device address, (3) the device is

not turned ON, and (4) the device is not connected via the serial interface.

• The “

xx” in the table indicates the device address. Specify the address that is

assigned to the device in the range of 01 to 99.

• You can only open one device at any given time.
• If a device is opened with the ESC O command, all commands are enabled on the

device.

• If a device is opened with the ESC O command, any other device that is open is

automatically closed.

• Normally, either CR+LF or LF can be used for the terminator in communication

commands. However, the terminator for these commands must be set to CR+LF.

Note

The ASCII code for ESC is 1BH. See appendix 1 for details.

5.1 Response Syntax

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