Advantech UNO-4672, Руководство пользователя

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19 Chapter 2
2.5.6 RS-485 Auto Flow & RS-422 Master/Slave Modes
You can set the “Auto Flow Control” mode of RS-485 or “Master/Slave”
mode of RS-422 by using the SW2 DIP switch for COM3~COM10.
Please also refer to Table 2.9 for the COM port mapping with the DIP.
In RS-485, if the switch is set to “Off”, the driver automatically senses
the direction of the data flow and switches the direction of transmission.
No handshaking is necessary.
In RS-422, if DIP switch is set to “On,” the driver is always enabled, and
always in high or low status. Please refer below for the default setting.
2.5.7 Redundant RS-422 Matter
In the occasion that UNO-4672 RS-422 ports need to act as multi-master
in parallel with other RS-422 master ports. Because of the auto detection
function, the TX port will also receive data from other RS-422 master. To
avoid this situation in this kind of application, user can use SW5~SW12
to turn it off, then no data will be received from TX port. Please refer to
the Table 2.11 for the COM port mapping and refer to Figure 2.3 for the
location.
Table 2.10: SW2 DIP Setting
SW2 Status Description
ON RS-422: Master mode
RS-485: N/A
OFF(Default) RS-422: Slave mode
RS-485: Auto flow control