Profibus connector TX indication Blinking on both line A & Line B of CI840
This is for my doubt regarding with a freelance 902 F controller with master field bus modues as CI930 with having 5 nodes, having slave module for each node is CI840. while some of my nodes i observed that profibus connector TX indication blinking on both Line A & Line B side( CI840 which is primary active showing TX indication blinking & also standby one also showing TX indication blinking )& while some nodes only Primary CI840 showing TX indication & standby one having no TX indication ). There is no error indication showing on profibus connector & also line redundancy of each nodes also working fine. so my doubt is due to this TX indication on both sides of CI840 is there problem with communication or redundancy issue ? can someone explain me about this why this happen ? below i attached a pic for reference.
The Primary CI840 will have Rx/Tx continuously on (solid), and the backup CI840 Rx/Tx will slow blink even while in DUAL; this is normal behavior. If they are not in DUAL, then you definitely have a problem, but the Rx/Tx should still slow blink on the backup. If Rx/Tx is completely off, then I don't think it can go into DUAL, and you have a bus problem. Might also want to double-check that the CI840's are set as Redundant in the project.
If you're asking about the TxD indication on the VIPA Profibus connector itself, then they should blink quickly according to bus activity, like an ethernet switch port.