NEC RS-232C user manual Code

The following shows the procedure for reading the temperatures from the sensors.

Step 1. Select a temperature sensor which you want to read.

Header	Message	Check	Delimiter
		code
SOH-'0'-Monitor ID-'0'-'E'-'0'-'A'	STX-'0'-'2'-'7'-'8'-'0'-'0'-'0'-'1'-ETX	BCC	CR

Header

SOH (01h): Start of Header

'0' (30h): Reserved

Monitor ID: Specify the Monitor ID which you want to get a value. Ex.) If Monitor ID is '1', specify 'A'.

'0' (30h): Message sender is the controller.

'E' (45h): Message Type is "Set parameter command".

'0'-'A' (30h, 41h): Message length is 10 bytes.

Message

STX (02h): Start of Message

'0'-'2' (30h, 32h): Operation code page number is 2.

'7'-'8' (37h, 38h): Operation code is 78h (on page 2).

'0'-'0'-'0'-'1' (30h, 30h, 30h, 31h): Select the temperature sensor #1 (01h). 00h: No meaning

01h: Sensor #1

02h: Sensor #2

03h: Sensor #3 ETX (03h): End of Message

Check code

BCC: Block Check Code

Refer to the section 4.5 “Check code” for a BCC calculation.

Delimiter

CR (0Dh): End of packet

Step 2. The monitor replies for confirmation.

Header	Message	Check	Delimiter
		code
SOH-'0'-'0'-Monitor ID-'F'-'1'-'2'	STX-'0'-'0'-'0'-'2'-'7'-'8'-'0'-'0'-'0'-'0'	BCC	CR

-'0'-'3'-'0'-'0'-'0'-'1'-ETX

Header

SOH (01h): Start of Header

'0' (30h): Reserved

'0' (30h): Message receiver is the controller.

Monitor ID: Indicates a replying Monitor ID.

Ex.) When this byte is set to 'A', the replying Monitor ID is '1'.

'F' (46h): Message Type is "Set parameter reply".

'1'-'2' (31h, 32h): Message length is 18 bytes.

Message

STX (02h): Start of Message

'0'-'0' (30h, 30h): Result code. No error.

'0'-'2' (30h, 32h): Operation code page number is 2.

'7'-'8' (37h, 38h): Operation code is 78h (in the page 2).

'0'-'0' (30h, 30h): This operation is "Set parameter" type.

'0'-'0'-'0'-'3' (30h, 30h, 30h, 33h): Number of temperature sensors are 3 (0003h).

'0'-'0'-'0'-'1' (30h, 30h, 30h, 31h): temperature sensor is #1.

ETX (03h): End of Message

Check code

BCC: Block Check Code

Refer to the section 4.5 “Check code” for a BCC calculation.

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