IDEC MicroSmart Pentra - Manual (Page 107)

W EB S ERVER CPU M ODULE U SER ’ S M ANUAL FC9Y-B1278 11-1
11: PING I
NSTRUCTION
Introduction
This chapter describes how to use the PING instruction. The PING instruction sends a ping packet to the specified remote
host to check if the communication can be done with the remote host on the Internet Protocol (IP) layer.
PING (Ping)
The PING instruction sends a ping packet to the specified remote host.
Symbol
Operation Details
When the input to the PING instruction is on, the PING instruction sends a ping packet to the remote host specified by S1.
Once the Web server CPU module receives the reply from the remote host, the completion output specified by D1 is
turned on, and the operation status (operation transition state and error code) is stored in the device specified by D2.
D2+1 is reserved for the system.
The PING instruction is executed when the input to the instruction is on. While the input to the PING instruction is on,
the PING instruction is continuously executed. To avoid executing PING instruction continuously, a transitional off-to-on
SOTU or on-to-off SOTD instruction should be used.
In order to use the PING instruction, the remote host list of the Web server CPU module should be configured. For details
about the remote host list, see “Remote Host List” on page 6-1.
Valid Devices
*1: Special internal relays cannot be used.
Devices in PING Instructions
S1 (Source 1)
Specify the remote host number. A constant or data register can be specified.
D1 (Destination 1)
Specify an internal relay or output as the completion output bit. When the Web server CPU module receives a reply from
the remote host, the completion output bit is turned on. The completion output bit is also turned on when there is no
reply from the remote host within the specified timeout that is configured in the Function Area Settings. For details
about the timeout setting, see “Programming WindLDR” on page 11-2.
D2 (Destination 2)
Specify a data register as the operation status. Destination 2 occupies two consecutive data registers starting with the
data register specified by D2. The operation status is stored in D2. D2+1 is reserved for the system. Data registers D0 to
D1998, D2000 to D7998, and D10000 to D49998 can be specified.
Device Function I Q M R T C D Constant Repeat
S1 Source 1 Remote host number - - - - - - X 1 - 255 -
D1 Destination 1 Completion output - X *1 - - - - - -
D2 Destination 2 Operation status - - - - - - X - -