diff -r fbe1ffaa56cf -r ea4a61b4a325 modbus/mb_utils.py
--- a/modbus/mb_utils.py	Wed Feb 24 15:36:37 2021 +0100
+++ b/modbus/mb_utils.py	Thu Feb 25 11:22:10 2021 +0100
@@ -186,7 +186,7 @@
 
     req_init_template = '''/*request %(locreqstr)s*/
 {"%(locreqstr)s", %(nodeid)s, %(slaveid)s, %(iotype)s, %(func_nr)s, %(address)s , %(count)s,
-DEF_REQ_SEND_RETRIES, 0 /* error_code */, 0 /* prev_code */, {%(timeout_s)d, %(timeout_ns)d} /* timeout */, %(write_on_change)d /* write_on_change */, 
+DEF_REQ_SEND_RETRIES, 0 /* mb_error_code */, 0 /* tn_error_code */, 0 /* prev_code */, {%(timeout_s)d, %(timeout_ns)d} /* timeout */, %(write_on_change)d /* write_on_change */, 
 {%(buffer)s}, {%(buffer)s}}'''
 
     timeout = int(GetCTVal(child, 4))