Moxa Technologies 1400, 1600, 1200 user manual Fast Flush

UPort 1200/1400/1600 Series User’s Manual			Driver Installation
	Tx Mode
	Setting	Factory Default	Necessity
	Hi-Performance,	Hi-Performance	Required
	Classical

To improve write performance, you can select the Hi-Performancemode. Under classical mode, the driver will not notify the user’s program that Tx is completed until all Tx data has been sent out from the UPort; this mode will cause lower throughput. If you want to ensure that all data is sent out before further processing, classical mode is recommended. Classical mode is the same as the COM Port behavior: The WriteFile() call will only finish when all queued data are sent out.

Fast Flush

Setting	Factory Default	Necessity
Enable/Disable	Enable	Required

1.For some applications, the user’s program will use the Win32 PurgeComm() function before it reads or writes data. With our design, after the program uses this PurgeComm() function, the UPort driver will keep querying UPort’s firmware several times to make sure that there is really no data queued in the UPort firmware buffer, rather than just flushing the local buffer. This kind of design is used because of some special considerations. However, it might take more time (about several hundred milliseconds) than a native COM1, because it needs to work via Ethernet. This is why the native COM ports on the motherboard can work fast with this function call, but UPort requires much more time.

2.To begin with, make sure there are some PurgeComm() functions being used in your application program. In this kind of situation, you might find that your UPort exhibits a much poorer operation performance than when using the native COM1 port. Once you have enabled the Fast Flush function, you can check to see if there has been an improvement in performance.

3.By default, the optional Fast Flush function is enabled, the UPort driver will work faster with PurgeComm().

4.Win32 Function PurgeComm() with PURGE_TXCLEAR will clear all queued Tx data. But for some applications, it will call this function for each transaction and result in low throughput. To avoid this, you can enable this function. The driver will only clear the data queued in the local buffer; it will not send firmware through the USB to clear the data queued in the firmware buffer.

Interface

UPort 1410, 1610-8, 1610-16

Setting	Factory Default	Necessity
RS-232	RS-232	Required
UPort 1250, 1250I, 1450, 1450I, 1650-8, 1650-16
Setting	Factory Default	Necessity
RS-232, RS-422,
4-wire RS-485, 2-wire	RS-232	Required
RS-485

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