(X61). If this instruction is executed when the flag (X61) is ON, the system relay SR9 (carry
flag CY) is set and the instruction is terminated without being executed.
● When the instruction is completed successfully, the system relay SR9 (carry flag CY) and the
system data register SD29 (Ethernet communication error code) are cleared.
■
Precautions for programming
● Insert the UNITSEL instruction immediately before this instruction and specify the unit (built-
in ET-LAN in the CPU unit) and the connection number.
● This instruction is not available in interrupt programs.
■
Operand [S] setting
Setting item Settings
Setting
range
S
Transfer
number
Specify the device address storing a transfer number or a
constant.
0 to 15
■
Timing chart
● The following diagram shows the process in which a transfer request is executed and data
transfer from a server to FP7 is completed successfully.
● The control relays (bit0 to bit15) can be monitored by using the ETSTAT instruction to read
and store their state in arbitrary operation devices.
Transfer request relay
ETSTAT [D] bit0
HTTP client preparation
done flag (X68)
(1) (2) (3) (4) (5) (6)
Transfer active relay
ETSTAT [D] bit1
Retry active relay
ETSTAT [D] bit2
Execution done relay
ETSTAT [D] bit3
Execution result relay
ETSTAT [D] bit4
Transfer direction relay
ETSTAT [D] bit5
Transfer cancel request
relay
ETSTAT [D] bit14
Transfer disable relay
ETSTAT [D] bit15
Turns OFF when transfer is requested.
Normal completion
Execution result relay: 0
Transfer done code: 0
Transfer direction relay
Server→PLC: 1
PLC→Server: 0
Ethernet initialization
active flag (X61)
(1) RUN (Power on) (4) Transfer request (Executes HTTPcREQ instruction)
(2) HTTP client preparation done (5) HTTP client login succeeded (Starts transfer)
17.18 HTTPcREQ (HTTP Client Transfer Request)
WUME-FP7CPUPGR-12 17-95