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Communication response time, Communication response time and time chart – KEYENCE DL-RS1A/FD-MH User Manual

Page 15

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13

Parameters of Commands and Responses

Error numbers

The following table lists the error numbers that are returned as error responses when errors occur in
the communication between DL-RS1A and FD-MH Series sensor amplifiers.
Each error number is identified with two digits (ASCII characters).

Commands can only be sent or received if a response is returned from DL-RS1A within 500 ms.
Take the appropriate action to resolve the problem by referring to "Troubleshooting" (page 17).

Error No.

Error name

Problem

Action

00

Invalid command

error

An invalid command was

received.

Make sure that the external device has

sent a command listed in

"Communication commands" (page 10).

20

Data length error

Data with the correct length was

not received.

Make sure that the external device has

sent either "CR" or "CR + LF" as a data

delimiter.

21

Number of

parameters error

The correct number of parameters

for the command was not

received.

Make sure that the number of parameters

and the positions of the commas used as

data delimiters conform to the command

format shown in "Commands and

Responses" (page 7).

22

Parameter error

·

A parameter exceeds its range of value.

·

The external device is trying to write a

data type that cannot be written.

·

The external device is trying to read a

data type that cannot be read.

·

The data format is incorrect.

Make sure that the external device is

sending a command listed in

"Communication commands" (page 10).

The sensor amplifiers are being

factory reset (initialized) or in the

start-up process after the power is

turned on.

Resend the command after the factory

reset (initialization) or start-up process is

complete.

29

Communication error

An error was detected with

RS-232C communication.

Make sure that DL-RS1A and the external

device have the same communication

settings configured. For information on

configuring DL-RS1A, refer to "(1)

Communication setup switches" (page 2).

65

ID number error

The ID number specified with the

command is incorrect.

Make sure that the sent data specified as

the ID number is a 2-digit number (ASCII

characters) according to the number of

connected units.

66

Expansion line error

The communication could not be

established due to a problem with

an expansion line.

Check that each of the sensor amplifiers

and DL-RS1A are securely and properly

connected by referring to "Connecting

the Unit to Sensor Amplifiers" (page 3).

Make sure that sensor amplifiers that are

supported by DL-RS1A are connected

(refer to page 4).

67

Write control error

DL-RS1A is not in a writable state.

Change the read/write setting switch to

the R/W position to enable writing to DL-

RS1A. For information on the read/write

setting switch, refer to "Part Names and

Functions" (page 2).

Point

Communication Response Time

This section describes the communication response time for each communication command and
various time frames.

Communication Response Time and Time Chart

This section describes the concept of communication response time and the time chart for the
communication commands.

When sending communication commands consecutively from the external device, wait to send
the next command after reception of the response for the previous command from DL-RS1A
completes.

SR command

The SR command directly reads data from a sensor amplifier during T4 (DL-RS1A command
processing time).

Time chart

M0 command and MS command

The M0 and MS commands read the buffered data that DL-RS1A periodically retrieves from the
sensor amplifiers.
Therefore, the latest data detected by the sensors can only be read after T2 (DL-RS1A data
processing time) where DL-RS1A retrieves data from the sensor amplifiers.

Point

External device

DL-RS1A

T5

T3

T4

T3: Command format send time from external device
T4: DL-RS1A command processing time
T5: Response send time from DL-RS1A

* For the specific values (times) of T3 to T5, refer to

"Time Frames of Communication Response Time" (page 14).

Sensor amplifier

DL-RS1A

T1

T2

External device

T3

T5

T4

T1: Sensor amplifier response time (Refer to the instruction manual of the sensor amplifier.)
T2: DL-RS1A data processing time
T3: Command format send time from external device
T4: DL-RS1A command processing time
T5: Response send time from DL-RS1A

Detection

* For the specific values (times) of T2 to T5, refer to

"Time Frames of Communication Response Time" (page 14).