IRMCHAN returns the channel number and the Ramtek device number used by the plot package (as assigned by RAMOPEN) for communicating with the Ramtek. Returns a negative value when the Ramtek package is not initialized or when the Ramtek channel is not yet assigned.
ich = IRMCHAN(id)
id (I): (returned) Ramtek device number
ich (I): (returned) Ramtek channel number
if ich <=0 the Ramtek is not is use.