Hitachi h252 and rs 485 connections

[Guest bithappy]

Hi, please help i am going mad. Has anybody ever interfaced a hitachi h 252 series plc using its 15 pin d connector from rs 485 or rs 422 convertors, ( adam 4520 units). I am using two convertors one at each end one at pc end and another at hitachi end tried everything to get these talking but i cant, it is so sad. I really appreciate your help if you have done this. Hitachi literature is hopeless.

[Guest Andre Tassone]

You have to connect the handshaking lines. You actually need an RS422 converter which also has the RTS/CTS signals. This requires a 9-wire connection! I have used the Alphatron A440 converters for this.