ION 7300 Modbus TCP - Voltages Reading Problem

[OnurGurhan]

Hi Everyony;

I can not read Voltage registers via Modbus TCP from ION 7300.

40011,40012,40013 register values are always 65535.

I wanna check modbus registers and firmware of 7300 so Im trying to connect ION setup via serial but i could not.(7300s are at the field has no Ethernet.)

How can i connect it ? Do you have any configuration ?

PS: I choose ION protocol, 9600 baud from device while trying to conncet ION setup

[Robert_Lee]

One thing to keep in mind is the ION73xx series of devices only allow a single connection to certain IP ports if using Ethernet (so if PME is already connected to the device via Ethernet, ION Setup would be unable to connect at the same time).

Also some of the serial ports are out-going connections *IF* the meter is equipped with either Ethernet (COM2) or a Modem (COM1).  The serial port is used to allow the meter to operate as a gateway to other devices so can no longer be used to communicate to the actual meter.

Ideally, you could use a ANSI optical probe to communicate via the front optical, or if the meter does have Ethernet, either connect using a direct cross-over cable or make sure to disable any other connections like PME or other software to allow ION Setup to connect to the device via TCP.  If you are attempting to communicate using the COM1 RS-485 port, you can also switch to view Comm diagnostics on the front panel to see if the meter is receiving and/or transmitting information (if your RS-485 converter is working properly).  You should also make sure ION Setup is using No Parity/8 data bits/1 stop bit for comm settings as that is the only settings the ION73xx meters support.

[Yut]

If you use serial port using ION Setup be sure to set timing, RTS and CTS both must be Disable whether connect via RS-485 port or optical port.

[OnurGurhan]

I think the error occurs because of PT Pri/Sec config.

PT Pri/Sec arraged as 34500/100. So we can see the 32300 Volt at the meter screen.

Voltage registers for 7300 are defined Unsigned16 so 32000 volts are over ranged for Unsigned 16 and sends 65530(over range value)

When i configured PT as 3450/100, i can read 3230 volt from these registers.. no problem.

In my opinion, it would fixed if I can convert it to "kV" at display or meter config.

How can i make it 32,3 kV ?? Its easy to make at 7650 but couldnt find it at 7300

Thanks in advance

[Robert_Lee]

One possible solution is to scale the Modbus Slave modules for voltages by setting the In Scaling larger than the Out Scaling (you will lose resolution and you would have to interpret the values on the Modbus side by multiplying the values back out.

Ex. 32303 would scale down by 10 to 3230 which is the value you would read via Modbus and then you would scale it back out by multiplying by 10 to 32300.

Another alternative would be to switch to 32 bit registers (either INT or UINT) depending on whether your master is capable of interpreting those formats.

[OnurGurhan]

I created new registers for voltages. I defined them 32 registers except of 16 unS. and FAILED

The problem is still continus. I think new register reads value from real voltage signal. (16 bit unS)