Issue
A SIM block in an LNC-100 has a diagnostic ERROR output = 159.
Environment
Network 8000 LNC-100
Cause
See the I/A Series MicroNet LON Network Controller manual, F-26566, Table 3.4, "SIM Block Error Codes", page 18:
"Could not read the NV information from the node.
NV index does not exist in the specified node. See Appendix A for NV index values.
OR
The node is possibly offline."
Resolution
Over the years, we have documented a few different cases of the ERROR = 159, and have found some different causes and resolutions.
1. On new installations, an incorrect data string in a SYS:SIM block could prevent the LNC-100 from communicating with any of the LON controllers, and every SIM block in the database would display ERROR = 159.
For example, in one case, the data string in the SYS:SIM block was "DOMAIN0=010000, SUBNET0=1,NODE0=127,ENGLISH,HEARTBEAT=120". Because the Domain address established by the network management tool used a one-byte address = 01, rather than the 3-byte address entered in the data string, the LNC-100 was not able to communicate with any LON devices. When the data string in the SYS:SIM block was edited to include the correct 1-byte Domain address, "DOMAIN0=01, SUBNET0=1,NODE0=127,ENGLISH,HEARTBEAT=120", the LNC-100 was able to communicate, and the diagnostic error in the SIM blocks was cleared.
In another case, setting the NODE0=15, saving the change, then setting it back to NODE0=127 in the data string of the SYS:SIM block enabled LON communications.
2. On existing installations that have been working OK for years, some of the SIM blocks show ERROR = 159, while other SIM blocks continue to communicate normally. Because the LNC-100 continues to communicate normally with some of the LON controllers, you can rule out hardware failure of the LNC-100.
a. The LON nodes (controllers) associated with the SIM blocks displaying the ERROR = 159 might be offline. Use NodeUtil to check the status of the node, and to set it online if possible.
b. The LON controller may have been replaced, and the replacement controller not assigned to the same Domain, Subnet, or Node as the original. The SIM block will not be able to identify the replacement, will display ERROR = 159. Use NodeUtil to identify the LON address of the replacement node(s), and a LON network management tool to assign its Domain, Subnet, and Node to be compatible with the information in the data string of the SYS:SIM block.
c. The LON controller may have been replaced by a newer model with a different profile, Program ID, and XIF file, so the points mapped in the SIM block no longer correspond exactly to the NVs in the newer profile. Use NodeUtil to extract the XIF file from the new controller, and check the NVs to determine if the NV index or SNVT type are different than those in the original controller. Edit the DATA field(s) in the SIM block to correspond to the new profile in the new controller.
