Discussion on issues related to the setup of ABB positioners
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It’s called a discussion, but in reality it’s about two issues I’ve encountered recently while using the ABB TZIDC positioners in practice; I’d like to consult everyone on them: 1. When the ABB positioner is operating automatically, if the menu interface is accessed, will it remain at the current valve position without making any changes? Does it only resume working once e*t reaches the operation interface? I’m asking this question because today, during the debugging process, I forgot to return to the operation interface. I then found that the DCS valve position output was set to closed, yet the control valve did not move. So I suspect this is the case, and I’d like to get everyone’s opinion on it ； 2. When checking the parameters of the positioners, it was found that the manufacturer’s technicians had selected angular travel for several positioners used with the top single-acting control valves. I checked the manual: the linear travel range is -30° to +30°, while the angular travel range is -60° to +60°. Can angular travel with self-tuning be used in place of linear travel? Is the linearity different? Is there any difference? I would like to ask everyone for advice regarding the above two questions**. Thank you!
The first question: when entering the menu screen, it’s unclear whether the given signal can trigger an action (I haven’t tried it, and it’s not meaningful anyway). Because when performing debugging and verification, it’s generally not advisable to assign values arbitrarily, as this can cause the system to get stuck. 2: The so-called angular travel and linear travel (I’m not sure exactly how to describe them). For example, in the case of a normally open valve, if the DCS output is 100% but the valve on site is closed, then by simply reversing the angular travel, the output will correspond to the actual condition of the valve. At this point, to find out that the corresponding current is 4 mA, you just need to reverse the linear motion. To what you call the valve position, the current corresponds accordingly!
Thank you for your reply. 1. The signal is not sent during the debugging of the valve body; this is because the control accuracy at that point is poor. I encountered this issue when I entered the menu interface to adjust the proportional and integral parameters in directory P7.0. It can be basically determined that on the menu interface, the current valve position will be maintained, and no valve position signals from the DCS will be received; it is as if the system has entered manual mode. 2. What you mentioned should refer to the parameter settings for P2.3 and P3.2. What I’m referring to is the installation style of the locator as defined in P1.0, with two options: LINEAR and ROTARY. For example, a single-acting control valve at the top is a straight-stroke valve, while a butterfly valve is an angle-stroke valve. However, what impact would it have if the top single-acting control valve accidentally selected ROTARY during initialization?
When the valve is not in automatic mode, the specified valves do not operate, including in the situation you mentioned – they also do not respond when entering the setup menu. I believe that the concept of angular travel applies to valves whose travel distance exceeds 60 degrees, or it relates to the parameters specific to angular travel valves; it has nothing to do with linear travel