SMC Networks HRL100-A, Operation Manual

Page: 42 / 56

HRX-OM-W069
Chapter 3 Serial communication
3.12 Negative response HRL Series
3-16
3.12 Negative response
A negative response is returned when the following request message
is received.
1) When unspecified function code is used.
2) An address out of range is specified.
3) The data field is not normal.
 Negative response message (Slave to Master)
1) Negative acknowledgment message frame in ASCII mode.
Start
Slave
Address
1)Function
2)Error
Code
LRC End
[:] XX XX XX XX XX XX XX XX [CR] [LF]
2) Negative acknowledgment message frame in RTU.
Start
Slave
Address
1)Function
2)Error
Code
CRC End
T1-T2-T3-T4

1
XX XX XX XX XX XX T1-T2-T3-T4


1
Silent interval for 3.5 characters
1) Function
Assign the value consisting of the request function code (hexadecimal
value) plus 80h.
Example 1) ASCII mode
Received function code: “04”(0000 0100)” ASCII code 30h, 34h
Abnormal function code: ”84”
（
1000 0100
） ” ASCII code 38h, 34h
Example 2) RTU mode
Receive function code: "04" (0000 0100)
Abnormal function code: "84" (1000 0100
）
2) Error Code
Assign error code below.
01 : Function code of a command is outside the standard
02 : The specified address of register is outside the range.
03 : Data field of a command is not normal.