Questions on the CTRIO I-box

[MichaelL65]

There are a couple of little quirky things that I'm a bit unclear on regarding the I-box in DirectSOFT for the CTRIO module.

1. The option for a 'local' module only allows me to enter 2 memory locations instead of the 4 I set up with the Work Bench. If I set that to EBC, then I can enter the 4. That seems to work even when the modules are in the local base, but I'm a bit uneasy about the reliability when I am obviously telling the program that it isn't local.

2. In the I-box it asks for a workspace - how big is this needing to be? Is in one V-memory location or a dozen? I haven't found any reference to this in the CTRIO or Work Bench documentation, and what I have found on the I-box instruction just says it is there.

My current project is using 4 CTRIOs, so I want to make sure they aren't stepping on each other.

Thanks in advance!

[franji1]

You have to have 4 ranges when doing the CTRIO is configured remotely via ERM.  However, it is recommended that you only use two ranges for your CTRIO config if it is local.  This is due to the fact that the "complete cycle" of data updates between the CTRIO module and the CPU is twice as long with 4 ranges versus 2.  If you have a 260, the CTRIO can usually do 2 transactions per PLC scan, so if you have 4 ranges, it will take 2 PLC scans.  If you only have 2 ranges configured, then it will do all transactions on every PLC scan.

Therefore, the distinction on the IBox is not 2 ranges vs. 4 ranges, but is it a remote CTRIO (which must use 4) or is it local (which SHOULD use 2).  You can configure it "remotely" with 4 ranges even if it is local, but you extend the latency with status and commands just a little bit.

The workspace registers in all of the IBoxes are 1 WORD long.  If there is a buffer (e.g. ECOM100 IBoxes), or a double-word parameter, the IBoxes would display a range (e.g. V2000-V2001 or V1400-V1500)

[MichaelL65]

OK, I can deal with that. The timing isn't crucial down to the scan level (which is only about 20ms anyway, IIRC), so taking an extra scan to update is not an issue. Thanks!