[ns] [help] problem of implementing node-up and node-down

[Bo Fu]

Hi,

I am using ns-2 2.31 to simulate. My idea is to to disable some mobile
in the middle of the simulation. I found there is a method: $node
node-down. But every time I use this method, the tcl script got no
error. However, when it runing to the half of the simulation time, an
error popped out:
ns: _o14 node-down:
    (_o19 cmd line 1)
    invoked from within
"_o19 cmd node-down"
    invoked from within
"catch "$self cmd $args" ret"
    invoked from within
"if [catch "$self cmd $args" ret] {
set cls [$self info class]
global errorInfo
set savedInfo $errorInfo
error "error when calling class $cls: $args" $..."
    (procedure "_o19" line 2)
    (SplitObject unknown line 2)
    invoked from within
"$mac_(0) node-down"
    (procedure "_o14" line 3)
    (Node/MobileNode node-down line 3)
    invoked from within
"_o14 node-down"

Anybody can help me with it? Thanks in advance.

Danny