Differences

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--- ess:ess_mode_2_and_3 [2019-08-15 12:39] – replace venus-device with GX device guy_stewart
+++ ess:ess_mode_2_and_3 [2020-02-10 16:00] – [5. Response times and ramp speed] mvader
@@ Line 256: / Line 256: @@
   * As an alternative to running the control loop externally, using ModbusTCP, it is also possible to run code on the CCGX itself and update the AcPowerSetpoint via D-Bus. We have one customer that is running a MQTT client on the CCGX, written in Python, that gets the control-loop output as updates from a MQTT broker. And the Python script sends them to the Multi, using D-Bus service com.victronenergy.vebus.ttyO1, and path /Hub4/AcPowerSetpoint
-===== 5. Response times =====
+===== 5. Response times and ramp speed =====
-Depending on which components are used, and from which point the communication is sent to the inverter, there are several factors involved in the response time: the Color Control GX, ModbusTCP, MK3 microprocessor, the Assistant, and the Multi itself.
+There are multiple factors that determine the response time to a (digital-) command to feed in:
-The (now deprecated) Hub-4 Assistant had no rate limiter.
+  - Latency and communication speed of all components in the communication chain: ModbusTCP or MQTT, GX Device, MK3 microprocessor, ESS Assistant, internal communication in the Multi itself.
+  - Rate limiting imposed by the used Country Grid code. Code "Other" has no rate limiting, Code "Europe" allows installer configurable rate limiting, many other codes have fixed a powerup ramp up.
-The ESS Assistant has a rate limiter. In the currently latest version (162) it is at 400W per second
+  - Hard coded rate limiting in the inverter/charger firmware: as per ESS version 162 it is set to 400W per second. The reason for this rate limiter is that without that there are regulation problems (overloads and such) when the mains is weak (long cables and such resulting in a relatively high impedance). More information on that [[ve.bus:grid-codes-and-loss-of-mains-detection|here]], as well as in the main ESS manual.
-Background: late 2016, we copied the Hub-4 Assistant, and named the copy "ESS Assistant". And then development on the Hub-4 Assistant was stopped. The reason for the rate limiting is that without that there are regulation problems (overloads and such) when the mains is weak (long cables and such resulting in a relatively high impedance). More information on that [[ve.bus:grid-codes-and-loss-of-mains-detection|here]], as well as in the main ESS manual.
 ===== 6. Further examples for external control =====