Controllogix Serial Comm's - Only ASCII?

skyfox

Lifetime Supporting Member
Join Date
Nov 2006
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CA
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Hello All,

I am trying to talk to a serial device via Controllogix L5550 Serial Port. Reading thru the device manual, it appears that communications are based on transfer of command bytes (1 Byte during each Send or recive transaction) between the Host (in this case The CONTROLLOGIX CPU), and the serial device.

Device manual mentions an optionally available Serial protocol that can use ASCII commands for communications, but it is not available for the Firmware revision of the device that I am currently trying to communicate with.

Basically Comm's goes like this.....

1) HOST Sends a Command "Byte" telling the device what it intends to do.

2) Device ECHO's back the Byte recived from the Host as an Ack.

3) Then the host sends Another command byte requesting the needed data.

4) Device acnowledges with an Echo

Etc. Etc.

I ve been palying around with the Logix COM Port talking between two controllogix processors, but communications are in ASCII.

How does one send/Receive "HEX/Binary" data using the Logix PLC's SERIAL Port?

Is it even possible or it is only capable of sending in ASCII mode?

Another question, how do I go about converting an "ASCII" character to get its "Decimal" equivalent in a ControlLogic CPU. (Version 16 & Higher). I could not locate an instruction that would support this.


Thanks a bunch
 
Last edited:

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