Lead For Mitsubishi Fx Direct Protocol Communication

[rabenson]

Hi,

Sorry if this is a bit basic but this is my first foray into using DaqFactory. I'm wanting to connect to a Mitsubishi FX1 PLC using the FX Direct protocol via the PLC's programming port. I note that the manual says that :

"The SC-09 cable will not work for Mitsubishi FX using this protocol."

I'm currently using a pattern type USB sc-09 cable and am receiving only a stream of \x95 whatever I try to send / receive.

Is there a particular lead that I should be using in place of the SC-09 or am I missing something else?

Thanks,

Ron

[AzeoTech]

The SC-09 cable doesn't pass the correct pins so your USB cable isn't going to work. Here's the pinout for the Fx Controller Port connector (RS422):

Pin:

1: RDA

2: TDB

3: short to pin 8

4: TDA

5: short to pin 6

6: short to pin 5

7: RDB

8: short to pin 3

[rabenson]

Thanks for your reply

Strangely enough, it now seems to be working with the SC-09 cable - I had the word length set to 8 instead of 7 and resetting this seems to have sorted it. the only problem that I am seeing is that I am occasionally getting a C1038 timing lag error while reading 7 output values at 0.2 second intervals - could the lead compatibility be causing this?

Do you know if a suitable "premade" lead is available?

Thanks

[AzeoTech]

I do not know of any premade leads, but perhaps someone else does.

As for the timing lag, 0.2 seconds is probably too fast for the PLC. Take a look at the monitor and see what the difference in time is between the Tx and Rx. Your minimum interval will need to be maybe 0.05 seconds larger than that.

[rabenson]

Problem solved - used a function to read the inputs rather than separate channel reads. Thanks for your help, much appreciated!