FCMND program instruction 501 Set DDCMP communication parameters. This command is recognized only by serial communication lines configured for use with the DDCMP protocol. See the eV+ Language User's Guide for the details of this command. TCP Command Codes 600 Initiate a close connection from the TCP server side for the client identified by the handle number handle in the instruction FCMND (lun, 600) $INTB(handle). Note, however, that close-connection requests are more commonly initiated by the client side. 601 Initiate a PING command (see the eV+ Operating System Reference Guide for details on the PING monitor command).
The resulting IOSTAT value is either 1, indicating the client was found on the network, or - 562, indicating a network timeout. eV+Language Reference Guide, v2.x, 18319-000 Rev A Page 224