ZETRON 640 DAPT XTRA, Руководство по установке и ремонту

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Communications Setup
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COM1 is at I/O address 03F8h and uses IRQ4
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COM2 is at I/O address 02F8h and uses IRQ3
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COM3 is at I/O address 03E8h and uses IRQ4
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COM4 is at I/O address 02E8h and uses IRQ3
Troubleshooting Checklist
To avoid potential serial port problems, check the following:
q Ensure that a serial port is present and addressed to COM1, COM2, COM3, or COM4.
Usually the COM port number is set by way of DIP switches on the serial board or
computer BIOS. Check your PC manuals for details.
q Ensure that the serial port is active. Some computers allow disabling/enabling of the
ports, usually by way of DIP switches. Check the PC and modem manuals for details.
q Ensure that the interrupts are set correctly and are active on the serial port. Some serial
boards or ports can be setup for use with any interrupt signal. Check for the correct IRQ
settings as listed above.
q
Ensure that there are no serial port conflicts. If the computer has two serial ports, one
must be COM1, the other COM2. If two ports are assigned the same COM port number,
neither will function reliably.
q
Recheck the pin configuration of the ZLINK cable, per Figure 11.
Note: Many PC cards perform several functions. For instance, a memory expansion card
may also have a serial port. It is important to note that the computer may have an
extra, unused serial port.
Modem Connections
Most modems on the market today function based on software commands instead of hardware
switches or jumpers. An “initialization string” of commands can be sent to the modem to
configure which features are enabled or disabled.
If the modem in the Model 640 responds to an incoming call, but a serial connection cannot be
established, then a revised modem initialization string may be required to disable some of the
default settings common in the newer, high-speed modems (14.4 Kbps and faster). The features
in the modem installed in the PC that typically need to be disabled are:
Data Compression
Error Correction
Flow Control
For example, the following set of commands would be appropriate to initialize a US Robotics
modem:
AT&M0&K0&I0&H0&N2