There are numerous issues which may prevent successful or sustained communication utilising the 1747-PIC module or 1747-PIC/AIC+ driver. These issues are not necessarily problems with the PC or software, but most commonly, they are features of newer PC hardware and software that interfere with the operation of the PIC driver.
Consult the list below and then check the system you're having problems with to determine if anything on the list may apply.
List of Issues:
USB to Serial converters: A USB to Serial converter will NOT work with the PIC driver/module. A standard serial port MUST be used. The converter is not capable of making the necessary timing conversions that the driver requires to translate from a DF1 protocol to DH-485. Systems without a COM port and only USB ports must use a 1784-PCMK card or 1747-UIC interface.
Infrared Ports: Infrared ports found on PCs or notebook computers should be disabled in the system BIOS or setup utility. Infrared ports commonly share resources with the COM ports on the system, thus they prevent the PIC driver from obtaining and using all required resources.
Power Management: All power management functions should be disabled in the system BIOS or setup utility. As with Infrared Ports, Power Management may prevent the PIC driver from obtaining and using the necessary resources from the COM ports. Also, if power management engages while using the PIC driver, the COM port resources may be completely inaccessible until a system reboot.
COM Port Settings: These are the proper COM port settings for use with the PIC module/driver. They can be changed through the Windows Control Panel using the Device Manager or in Windows NT, through Ports. Bits/sec - 9600, data bits - 8, Parity - None, 1, Flow Control - None, under "Advanced" - Disable FIFO buffers (un-check the box that says "Use FIFO buffers")
ACPI: ACPI stands for Advanced Configuration and Power Interface and is found only on the Windows 2000 and Windows XP operating systems. Not all computers are adversely affected by ACPI, but if necessary, ACPI should be disabled both in the Windows environment and in the system BIOS or setup utility (not all systems have ACPI options in the BIOS). Please consult article A9801
Anti-Virus Software: In extremely rare cases, some anti-virus programs may be monitoring the system COM ports and prevent RSLinx from obtaining the required resources for the PIC driver. Try temporarily disabling the anti-virus software or services.
User Privileges: When attempting to configure any driver in RSLinx, local administrative privileges are required. Some drivers may configure without these privileges, but they may not function properly. Once configured, all drivers can be run from a standard user account. This will only be applicable in a Windows NT or 2000 environment.
Hardware Problems: 1747-PIC modules, PC COM ports and serial cables occasionally go bad. If you've tried all the options above and are still unsuccessful, try switching hardware and/or computers. You may also consider using a 1784-PCMK card (PCMCIA bus) for laptops or either a 1784-PKTX card (PCI bus) or 1784-KTX card (ISA bus) for desktops.
Serial Expansion Cards: The PIC module/driver will not work on PCMCIA serial cards as well as most other serial expansion cards. Also, if you configure a PIC driver, and <SPAN style="FONT-SIZE: 9pt; COLOR: #444444; FONT-FAMILY: Arial">you have a serial expansion card, RSLinx 2.3x may GPF on startup. See tech note