FP2 Serial Data UnitPrecautions Regarding Serial Data Unit Operation and Programs5 − 65.2 Precautions Concerning Communication5.2.4 Precautions Concerning a Software ResetIf the serial data unit need to be reset because something irregular has occurred, thereset can be done through the software, but the following precautions should beobserved.• A software reset occurs when Y1D is turned on in the sequenceprogram.• After the software reset is received, it takes approximately100 msec for initialization to be completed.• After initialization has been completed, XE goes on.• When a software reset is carried out, please be aware that bothchannels, channel 1 and channel 2, are reset.If an error occurs on one channel but communication is beingcarried out normally on the other, a software reset will also clear theflags and buffers of the other channel, so please use the softwarereset function cautiously.5.2.5 Precautions When Setting the Control Signals CS and CD to “Valid”NoteWhen using two channels (COM1 and COM2) setting the controlsignals CS and CD to “Valid”, the CS of external device should bealways on.If the CS is off, the communication service of the other channelwill stop.
