On the production server:
Jul 11 16:59:38 h1conlog1-master conlog: ../conlog.cpp: 301: process_cac_messages: MySQL Exception: Error: Out of range value for column 'value' at row 1: Error code: 1264: SQLState: 22003: Exiting.
On the test stand server:
Jul 11 16:59:40 conlog-test-master conlogd: ../database.cpp: 828: insert_dbr_double_values_execute: Error executing m_p_insert_dbr_double_value_prep_stmt. Parameters: H1:OMC-READOUT_ERR_GAIN, 1436659172531946392, 0, -nan, 0, 0.
Jul 11 16:59:40 conlog-test-master conlogd: ../conlog.cpp: 314: process_cac_messages: MySQL Exception: Error: Out of range value for column 'value' at row 1: Error code: 1264: SQLState: 22003: Exiting.
So it would appear that H1:OMC-READOUT_ERR_GAIN got a value of -nan which the MySQL server could not store.