Sato 8400 printers connected to two PC communication ports. Printers are using the traditional Sato serial cables. Protocol setup on the printers is "PC1 RS On/Off."

When either printer is off-line and jobs are sent to both printers, the second printer will not print until the first printer is put back on-line.

Change the cables to the Sato Bi-Directinal serial Cables. Set the protocol on the printers to "Status 2." In Easylabel's Printer configuration menu, set "Bi-Directional to "Y"