Modbus Tcp addressing > 9999

Hi All,

I have a temperature controller that doesn’t have custom Modbus map feature. So at the moment the addressing is all over the place. I am only interested 10~15 floating point registers, but the holding register addresses are for e.g 16570, 28905, 29170 etc

I am able to read the addresses on a Modbus software, now I am trying to map it on ignition gateway.

Looking at the help for Modbus Tcp addressing in Ignition help, I see the address range is 0~9999.

Does this mean I would need a Modbus aggregator between ignition and temperature controller to map the addresses to 0 ~9999 range.


Saurabh Menon.

The address range is not limited to 9999, I’m not sure where you’re seeing that.

@Kevin.Herron thanks for the speedy reply.

screen shot attached , last

Seems you’ve found an error in the documentation.

1 Like

@pturmel thanks for the feedback.

Yeah, that’s definitely wrong.

Since you only need 10-15 sporadic tags I wouldn’t even use the address mapping, just make the OPC tags in the Ignition Designer and address them manually.


Out of curiosity, what is the advantage of mapping the addresses in the gateway vs ignition designer

I have seen a similar documentation error in the Siemens s1200 mapping. I have a S1215 controller that was connected to Ignition 7.9.

The address text was case sensitive, I could not get data for ‘IX0.0’ but ‘ix0.0’ was working.

Will update with the actual address later.

Mapping makes the addresses usable in the OPC Quick Client via the gateway web page, and it makes those addresses visible in the designer’s OPC Browser, from which you can drag and drop. The downside is that Ignition tags or other access that point at mapped names won’t work if the mapping isn’t present. As a side effect of duplicating devices, perhaps.

In the interest of posterity, I’ve removed the statement in the documentation that suggested the address range was limited to 9999. We apologize for any trouble this caused.

1 Like