YOKOGAWA UTAdvanced Series, User Manual

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4-6
IM 05P07A01-01EN
4.4.3 Requests and Responses

01 Reading multiple I relays

Function
The content of I relays is read continuously for the specified number of relays from the
specified I relay No.
• The maximum number of relays that can be read at a time is 256.
• For details on the response format at an error, see “4.4.4 Response Error Codes.”
• The response status of I relays is one bit for each I relay.
The bit indicates: 1 = ON and 0 = OFF. The LSB of the first data item indicates the
status of the read start I relay.
If the status of I relay Nos. 20 to 27 is supposed to be ON-ON-OFF-OFF-ON-OFF-
ON-OFF, it is expressed as 01010011 (0x53) in the binary number.
The status of eight I relays is represented by one byte. If the maximum number of I
relays is short of eight I relays in the last data item, the remaining empty space is filled
with zero.

Request (during normal operation) Read n number of data
Element MBAP Header PDU
Number of bytes 2 2 2 1 1 2 2
Command
element
Transfer ID Protocol ID Number of
bytes
Unit ID Function code I relay start No. Number of
I relays
(Hex) Optional value 0000 0006 01 01 n

Response (during normal operation)
Element MBAP Header PDU
Number of bytes 2 2 2 1 1 1 1 1
Command
element
Transfer ID Protocol ID Number of
bytes
Unit ID Function
code
Byte count
(Note 1)
I relay
content 1
• • • I relay
content N
(Hex) Optional value 0000 N+3 01 01 N
Note 1: When the byte count is assumed to be “N,” N = Number of read I relays / 8 (however, N = N
+ 1 when the remainder is not zero).

03 Reading multiple D registers

Function
The content of D registers is read continuously for the specified number of registers from
the specified D register No.
• The maximum number of registers that can be read at a time is 100.
• For details on the response format at an error, see “4.4.4 Response Error Codes.”

Request (during normal operation) Read n number of data
Element MBAP Header PDU
Number of bytes 2 2 2 1 1 2 2
Command
element
Transfer ID Protocol ID Number of
bytes
Unit ID Function code Register start
No.
Number of
registers
(Hex) Optional value 0000 0006 01 03 n

Response (during normal operation)
Element MBAP Header PDU
Number of bytes 2 2 2 1 1 1 2 2
Command
element
Transfer ID Protocol ID Number of
bytes
Unit ID Function
code
Byte count Register
content 1
• • • Register
content n
(Hex) Optional value 0000 2n+3 01 03 2n
4.4 Communication with Host Computer