Multi-Tech Systems FR111 owner manual Channel Device

The Word Length option sets the number of bits in a word. The word length range is 5 to 8 bits. The default is 8 bits.

The Stop Bits option sets the number of stop bits. The number of stop bits can be 1, 1.5, or 2. The default is 1 bit.

The Parity option sets parity for odd, even or none. Under normal conditions, parity is set to none. The default is none.

The Flow Control option allows for two types of flow control: the soft- ware-based XON/XOFF and the hardware-based Clear to Send (CTS). The default condition is CTS. Flow control is the means by which data flow from the device into the MultiFRAD is controlled. Flow control is necessary when the data handling capacity of the data port cannot keep up with the volume of data sent to it. When the data device controls data flow to itself, it is called pacing (see Pacing option). The combination of flow control from the port device and pacing to the data device is how data transfers are regulated so that no data is lost.

MultiFRAD-INITIATED	CHANNEL DEVICE-
FLOW CONTROL	INITIATED PACING

DATA

ChannelMultiFRAD Device

Flow control stops the input of data to the MultiFRAD

DATA

ChannelMultiFRAD Device

Pacing stops the output of data from the MultiFRAD

The Enq/Ack Flow Control option is a special flow control protocol used in Hewlett Packard computer systems. This option is sometimes referred to as Enquire/Acknowledge flow control because it’s based on the computer sending an enquiry (ENQ) and then expecting an ac- knowledgment (ACK). The default condition for this option is off.

The Echo option enables data entered on the data device keyboard to be returned to the device's monitor. The purpose of this option is so that an operator will not experience undue delays in seeing entered data appear on their monitor. The default condition for the echo option is off.

The Pacing option controls the data flow to the data device. This option only applies to the async mode of operation. Pacing is necessary when the flow of data to a device operating on the data port is more than it can process. If the device cannot process the volume of data sent to it, then the pacing option should be turned on. The pacing method used is determined by the type of flow control. The default condition is for this option to be turned off.

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