KB80557
Published: April 16, 2009
Revision: 1.0

PAC-S RS-232 ports unresponsive when used with Mistic I/O units


Applies To:

SNAP-PAC-S1
SNAP-PAC-S2

Versions Affected:

Problem was discovered in version: R8.4a


Symptoms:

SNAP PAC S-series controller RS-232 ports are unresponsive when used to communicate to Mistic I/O units. The RS-232 port's transmit LED (TX0–TX3) is active (lights) when the controller initially attempts a serial connection. Subsequent attempts to connect serially results in no activity from the port's transmit LED.

For example, the problem occurs in an application where a modem is connected to the controller's RS-232 port (Port 0–3) in order to communicate to a remote serial (RS-485) Mistic I/O unit. The remote Mistic I/O unit communicates to the controller's RS-232 port via an RS-232 to RS-485 converter, and then through a modem.

Both Mistic ASCII and Mistic binary protocol exhibit the problem.


Resolution:

Opto 22 is investigating this issue.


Questions?

Contact: Opto 22 Product Support.
Phone: 800-835-6786 or 951-695-3080
Email: support@opto22.com


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